Chapter 55: Perimeter and Rectangle Area

Learn Grade 4 mathematics with very-beginner explanations, original worked examples, practice, reasoning, and review.

Grade 4Beginner Friendly10 Examples Per Topic30 Q&APractice + Review

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Chapter Overview

This chapter teaches Perimeter and Rectangle Area in original, simple language with step-by-step reasoning, worked examples, practice exercises, common mistakes, and review questions.

55.1 Meaning of perimeter

Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see. Work one step at a time, use a model or number sentence when useful, and check whether the answer is reasonable.

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Find the perimeter of a 9 cm by 4 cm rectangle.

Add all four side lengths.
2 × (9+4) = 26.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 26 cm

Worked Example 2

Problem: Find the perimeter of a 8 cm by 6 cm rectangle.

Add all four side lengths.
2 × (8+6) = 28.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 28 cm

Worked Example 3

Problem: Find the perimeter of a 11 cm by 7 cm rectangle.

Add all four side lengths.
2 × (11+7) = 36.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 36 cm

Worked Example 4

Problem: Find the perimeter of a 3 cm by 6 cm rectangle.

Add all four side lengths.
2 × (3+6) = 18.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 18 cm

Worked Example 5

Problem: Find the perimeter of a 9 cm by 6 cm rectangle.

Add all four side lengths.
2 × (9+6) = 30.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 30 cm

Worked Example 6

Problem: Find the perimeter of a 3 cm by 3 cm rectangle.

Add all four side lengths.
2 × (3+3) = 12.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 12 cm

Worked Example 7

Problem: Find the perimeter of a 11 cm by 7 cm rectangle.

Add all four side lengths.
2 × (11+7) = 36.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 36 cm

Worked Example 8

Problem: Find the perimeter of a 9 cm by 8 cm rectangle.

Add all four side lengths.
2 × (9+8) = 34.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 34 cm

Worked Example 9

Problem: Find the perimeter of a 11 cm by 9 cm rectangle.

Add all four side lengths.
2 × (11+9) = 40.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 40 cm

Worked Example 10

Problem: Find the perimeter of a 9 cm by 8 cm rectangle.

Add all four side lengths.
2 × (9+8) = 34.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 34 cm

Practice Exercise

Create and solve one new example of Meaning of perimeter. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

55.2 Perimeter of a rectangle

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Find the perimeter of a 9 cm by 4 cm rectangle.

Add all four side lengths.
2 × (9+4) = 26.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 26 cm

Worked Example 2

Problem: Find the perimeter of a 4 cm by 7 cm rectangle.

Add all four side lengths.
2 × (4+7) = 22.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 22 cm

Worked Example 3

Problem: Find the perimeter of a 6 cm by 4 cm rectangle.

Add all four side lengths.
2 × (6+4) = 20.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 20 cm

Worked Example 4

Problem: Find the perimeter of a 3 cm by 4 cm rectangle.

Add all four side lengths.
2 × (3+4) = 14.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 14 cm

Worked Example 5

Problem: Find the perimeter of a 12 cm by 5 cm rectangle.

Add all four side lengths.
2 × (12+5) = 34.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 34 cm

Worked Example 6

Problem: Find the perimeter of a 6 cm by 2 cm rectangle.

Add all four side lengths.
2 × (6+2) = 16.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 16 cm

Worked Example 7

Problem: Find the perimeter of a 12 cm by 2 cm rectangle.

Add all four side lengths.
2 × (12+2) = 28.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 28 cm

Worked Example 8

Problem: Find the perimeter of a 7 cm by 5 cm rectangle.

Add all four side lengths.
2 × (7+5) = 24.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 24 cm

Worked Example 9

Problem: Find the perimeter of a 4 cm by 7 cm rectangle.

Add all four side lengths.
2 × (4+7) = 22.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 22 cm

Worked Example 10

Problem: Find the perimeter of a 3 cm by 2 cm rectangle.

Add all four side lengths.
2 × (3+2) = 10.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 10 cm

Practice Exercise

Create and solve one new example of Perimeter of a rectangle. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

55.3 Perimeter of a square

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Find the perimeter of a 3 cm by 2 cm rectangle.

Add all four side lengths.
2 × (3+2) = 10.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 10 cm

Worked Example 2

Problem: Find the perimeter of a 5 cm by 8 cm rectangle.

Add all four side lengths.
2 × (5+8) = 26.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 26 cm

Worked Example 3

Problem: Find the perimeter of a 4 cm by 4 cm rectangle.

Add all four side lengths.
2 × (4+4) = 16.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 16 cm

Worked Example 4

Problem: Find the perimeter of a 12 cm by 9 cm rectangle.

Add all four side lengths.
2 × (12+9) = 42.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 42 cm

Worked Example 5

Problem: Find the perimeter of a 8 cm by 6 cm rectangle.

Add all four side lengths.
2 × (8+6) = 28.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 28 cm

Worked Example 6

Problem: Find the perimeter of a 3 cm by 2 cm rectangle.

Add all four side lengths.
2 × (3+2) = 10.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 10 cm

Worked Example 7

Problem: Find the perimeter of a 4 cm by 5 cm rectangle.

Add all four side lengths.
2 × (4+5) = 18.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 18 cm

Worked Example 8

Problem: Find the perimeter of a 12 cm by 4 cm rectangle.

Add all four side lengths.
2 × (12+4) = 32.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 32 cm

Worked Example 9

Problem: Find the perimeter of a 7 cm by 7 cm rectangle.

Add all four side lengths.
2 × (7+7) = 28.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 28 cm

Worked Example 10

Problem: Find the perimeter of a 3 cm by 8 cm rectangle.

Add all four side lengths.
2 × (3+8) = 22.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 22 cm

Practice Exercise

Create and solve one new example of Perimeter of a square. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

55.4 Missing side from perimeter

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Find the perimeter of a 9 cm by 3 cm rectangle.

Add all four side lengths.
2 × (9+3) = 24.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 24 cm

Worked Example 2

Problem: Find the perimeter of a 8 cm by 3 cm rectangle.

Add all four side lengths.
2 × (8+3) = 22.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 22 cm

Worked Example 3

Problem: Find the perimeter of a 6 cm by 9 cm rectangle.

Add all four side lengths.
2 × (6+9) = 30.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 30 cm

Worked Example 4

Problem: Find the perimeter of a 10 cm by 5 cm rectangle.

Add all four side lengths.
2 × (10+5) = 30.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 30 cm

Worked Example 5

Problem: Find the perimeter of a 4 cm by 7 cm rectangle.

Add all four side lengths.
2 × (4+7) = 22.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 22 cm

Worked Example 6

Problem: Find the perimeter of a 11 cm by 9 cm rectangle.

Add all four side lengths.
2 × (11+9) = 40.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 40 cm

Worked Example 7

Problem: Find the perimeter of a 9 cm by 8 cm rectangle.

Add all four side lengths.
2 × (9+8) = 34.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 34 cm

Worked Example 8

Problem: Find the perimeter of a 5 cm by 4 cm rectangle.

Add all four side lengths.
2 × (5+4) = 18.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 18 cm

Worked Example 9

Problem: Find the perimeter of a 6 cm by 3 cm rectangle.

Add all four side lengths.
2 × (6+3) = 18.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 18 cm

Worked Example 10

Problem: Find the perimeter of a 8 cm by 6 cm rectangle.

Add all four side lengths.
2 × (8+6) = 28.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 28 cm

Practice Exercise

Create and solve one new example of Missing side from perimeter. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

55.5 Meaning of area

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Find the area of a 11 cm by 6 cm rectangle.

Use area = length × width.
11 × 6 = 66.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 66 cm²

Worked Example 2

Problem: Find the area of a 4 cm by 5 cm rectangle.

Use area = length × width.
4 × 5 = 20.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 20 cm²

Worked Example 3

Problem: Find the area of a 5 cm by 5 cm rectangle.

Use area = length × width.
5 × 5 = 25.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 25 cm²

Worked Example 4

Problem: Find the area of a 5 cm by 8 cm rectangle.

Use area = length × width.
5 × 8 = 40.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 40 cm²

Worked Example 5

Problem: Find the area of a 4 cm by 3 cm rectangle.

Use area = length × width.
4 × 3 = 12.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 12 cm²

Worked Example 6

Problem: Find the area of a 6 cm by 4 cm rectangle.

Use area = length × width.
6 × 4 = 24.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 24 cm²

Worked Example 7

Problem: Find the area of a 5 cm by 9 cm rectangle.

Use area = length × width.
5 × 9 = 45.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 45 cm²

Worked Example 8

Problem: Find the area of a 7 cm by 2 cm rectangle.

Use area = length × width.
7 × 2 = 14.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 14 cm²

Worked Example 9

Problem: Find the area of a 10 cm by 5 cm rectangle.

Use area = length × width.
10 × 5 = 50.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 50 cm²

Worked Example 10

Problem: Find the area of a 10 cm by 6 cm rectangle.

Use area = length × width.
10 × 6 = 60.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 60 cm²

Practice Exercise

Create and solve one new example of Meaning of area. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

55.6 Square units

Square units is an important Grade 4 mathematics idea in Perimeter and Rectangle Area. Understand the meaning first, then use a clear representation or strategy and check whether the answer makes sense. Work one step at a time, use a model or number sentence when useful, and check whether the answer is reasonable.

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Create a simple Grade 4 example about Square units using the numbers 17 and 2.

Identify what the topic means.
Use the numbers in a way that follows the rule.
Check that the result or representation makes sense.

Very beginner explanation: Meaning comes first; the numbers should illustrate the concept clearly.

Answer: A correct example that demonstrates Square units.

Worked Example 2

Problem: Create a simple Grade 4 example about Square units using the numbers 2 and 8.

Identify what the topic means.
Use the numbers in a way that follows the rule.
Check that the result or representation makes sense.

Very beginner explanation: Meaning comes first; the numbers should illustrate the concept clearly.

Answer: A correct example that demonstrates Square units.

Worked Example 3

Problem: Create a simple Grade 4 example about Square units using the numbers 14 and 11.

Identify what the topic means.
Use the numbers in a way that follows the rule.
Check that the result or representation makes sense.

Very beginner explanation: Meaning comes first; the numbers should illustrate the concept clearly.

Answer: A correct example that demonstrates Square units.

Worked Example 4

Problem: Create a simple Grade 4 example about Square units using the numbers 2 and 14.

Identify what the topic means.
Use the numbers in a way that follows the rule.
Check that the result or representation makes sense.

Very beginner explanation: Meaning comes first; the numbers should illustrate the concept clearly.

Answer: A correct example that demonstrates Square units.

Worked Example 5

Problem: Create a simple Grade 4 example about Square units using the numbers 7 and 12.

Identify what the topic means.
Use the numbers in a way that follows the rule.
Check that the result or representation makes sense.

Very beginner explanation: Meaning comes first; the numbers should illustrate the concept clearly.

Answer: A correct example that demonstrates Square units.

Worked Example 6

Problem: Create a simple Grade 4 example about Square units using the numbers 12 and 8.

Identify what the topic means.
Use the numbers in a way that follows the rule.
Check that the result or representation makes sense.

Very beginner explanation: Meaning comes first; the numbers should illustrate the concept clearly.

Answer: A correct example that demonstrates Square units.

Worked Example 7

Problem: Create a simple Grade 4 example about Square units using the numbers 10 and 13.

Identify what the topic means.
Use the numbers in a way that follows the rule.
Check that the result or representation makes sense.

Very beginner explanation: Meaning comes first; the numbers should illustrate the concept clearly.

Answer: A correct example that demonstrates Square units.

Worked Example 8

Problem: Create a simple Grade 4 example about Square units using the numbers 10 and 2.

Identify what the topic means.
Use the numbers in a way that follows the rule.
Check that the result or representation makes sense.

Very beginner explanation: Meaning comes first; the numbers should illustrate the concept clearly.

Answer: A correct example that demonstrates Square units.

Worked Example 9

Problem: Create a simple Grade 4 example about Square units using the numbers 17 and 17.

Identify what the topic means.
Use the numbers in a way that follows the rule.
Check that the result or representation makes sense.

Very beginner explanation: Meaning comes first; the numbers should illustrate the concept clearly.

Answer: A correct example that demonstrates Square units.

Worked Example 10

Problem: Create a simple Grade 4 example about Square units using the numbers 17 and 15.

Identify what the topic means.
Use the numbers in a way that follows the rule.
Check that the result or representation makes sense.

Very beginner explanation: Meaning comes first; the numbers should illustrate the concept clearly.

Answer: A correct example that demonstrates Square units.

Practice Exercise

Create and solve one new example of Square units. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

55.7 Area of a rectangle

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Find the area of a 10 cm by 2 cm rectangle.

Use area = length × width.
10 × 2 = 20.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 20 cm²

Worked Example 2

Problem: Find the area of a 5 cm by 5 cm rectangle.

Use area = length × width.
5 × 5 = 25.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 25 cm²

Worked Example 3

Problem: Find the area of a 3 cm by 4 cm rectangle.

Use area = length × width.
3 × 4 = 12.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 12 cm²

Worked Example 4

Problem: Find the area of a 12 cm by 2 cm rectangle.

Use area = length × width.
12 × 2 = 24.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 24 cm²

Worked Example 5

Problem: Find the area of a 11 cm by 6 cm rectangle.

Use area = length × width.
11 × 6 = 66.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 66 cm²

Worked Example 6

Problem: Find the area of a 3 cm by 5 cm rectangle.

Use area = length × width.
3 × 5 = 15.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 15 cm²

Worked Example 7

Problem: Find the area of a 10 cm by 5 cm rectangle.

Use area = length × width.
10 × 5 = 50.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 50 cm²

Worked Example 8

Problem: Find the area of a 5 cm by 7 cm rectangle.

Use area = length × width.
5 × 7 = 35.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 35 cm²

Worked Example 9

Problem: Find the area of a 6 cm by 2 cm rectangle.

Use area = length × width.
6 × 2 = 12.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 12 cm²

Worked Example 10

Problem: Find the area of a 6 cm by 6 cm rectangle.

Use area = length × width.
6 × 6 = 36.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 36 cm²

Practice Exercise

Create and solve one new example of Area of a rectangle. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

55.8 Area of a square

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Find the area of a 5 cm by 8 cm rectangle.

Use area = length × width.
5 × 8 = 40.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 40 cm²

Worked Example 2

Problem: Find the area of a 8 cm by 9 cm rectangle.

Use area = length × width.
8 × 9 = 72.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 72 cm²

Worked Example 3

Problem: Find the area of a 7 cm by 6 cm rectangle.

Use area = length × width.
7 × 6 = 42.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 42 cm²

Worked Example 4

Problem: Find the area of a 8 cm by 7 cm rectangle.

Use area = length × width.
8 × 7 = 56.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 56 cm²

Worked Example 5

Problem: Find the area of a 12 cm by 8 cm rectangle.

Use area = length × width.
12 × 8 = 96.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 96 cm²

Worked Example 6

Problem: Find the area of a 11 cm by 7 cm rectangle.

Use area = length × width.
11 × 7 = 77.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 77 cm²

Worked Example 7

Problem: Find the area of a 3 cm by 7 cm rectangle.

Use area = length × width.
3 × 7 = 21.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 21 cm²

Worked Example 8

Problem: Find the area of a 8 cm by 2 cm rectangle.

Use area = length × width.
8 × 2 = 16.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 16 cm²

Worked Example 9

Problem: Find the area of a 7 cm by 6 cm rectangle.

Use area = length × width.
7 × 6 = 42.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 42 cm²

Worked Example 10

Problem: Find the area of a 12 cm by 9 cm rectangle.

Use area = length × width.
12 × 9 = 108.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 108 cm²

Practice Exercise

Create and solve one new example of Area of a square. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

55.9 Connecting arrays and area

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Find the area of a 12 cm by 4 cm rectangle.

Use area = length × width.
12 × 4 = 48.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 48 cm²

Worked Example 2

Problem: Find the area of a 11 cm by 6 cm rectangle.

Use area = length × width.
11 × 6 = 66.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 66 cm²

Worked Example 3

Problem: Find the area of a 10 cm by 2 cm rectangle.

Use area = length × width.
10 × 2 = 20.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 20 cm²

Worked Example 4

Problem: Find the area of a 4 cm by 2 cm rectangle.

Use area = length × width.
4 × 2 = 8.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 8 cm²

Worked Example 5

Problem: Find the area of a 8 cm by 7 cm rectangle.

Use area = length × width.
8 × 7 = 56.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 56 cm²

Worked Example 6

Problem: Find the area of a 12 cm by 3 cm rectangle.

Use area = length × width.
12 × 3 = 36.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 36 cm²

Worked Example 7

Problem: Find the area of a 8 cm by 2 cm rectangle.

Use area = length × width.
8 × 2 = 16.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 16 cm²

Worked Example 8

Problem: Find the area of a 5 cm by 4 cm rectangle.

Use area = length × width.
5 × 4 = 20.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 20 cm²

Worked Example 9

Problem: Find the area of a 10 cm by 2 cm rectangle.

Use area = length × width.
10 × 2 = 20.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 20 cm²

Worked Example 10

Problem: Find the area of a 5 cm by 4 cm rectangle.

Use area = length × width.
5 × 4 = 20.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 20 cm²

Practice Exercise

Create and solve one new example of Connecting arrays and area. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

55.10 Finding a missing side from area

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Find the area of a 10 cm by 6 cm rectangle.

Use area = length × width.
10 × 6 = 60.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 60 cm²

Worked Example 2

Problem: Find the area of a 12 cm by 3 cm rectangle.

Use area = length × width.
12 × 3 = 36.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 36 cm²

Worked Example 3

Problem: Find the area of a 7 cm by 2 cm rectangle.

Use area = length × width.
7 × 2 = 14.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 14 cm²

Worked Example 4

Problem: Find the area of a 9 cm by 2 cm rectangle.

Use area = length × width.
9 × 2 = 18.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 18 cm²

Worked Example 5

Problem: Find the area of a 4 cm by 3 cm rectangle.

Use area = length × width.
4 × 3 = 12.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 12 cm²

Worked Example 6

Problem: Find the area of a 9 cm by 3 cm rectangle.

Use area = length × width.
9 × 3 = 27.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 27 cm²

Worked Example 7

Problem: Find the area of a 5 cm by 4 cm rectangle.

Use area = length × width.
5 × 4 = 20.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 20 cm²

Worked Example 8

Problem: Find the area of a 5 cm by 2 cm rectangle.

Use area = length × width.
5 × 2 = 10.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 10 cm²

Worked Example 9

Problem: Find the area of a 6 cm by 4 cm rectangle.

Use area = length × width.
6 × 4 = 24.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 24 cm²

Worked Example 10

Problem: Find the area of a 7 cm by 9 cm rectangle.

Use area = length × width.
7 × 9 = 63.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 63 cm²

Practice Exercise

Create and solve one new example of Finding a missing side from area. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

55.11 Perimeter versus area

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Find the perimeter of a 4 cm by 7 cm rectangle.

Add all four side lengths.
2 × (4+7) = 22.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 22 cm

Worked Example 2

Problem: Find the perimeter of a 9 cm by 9 cm rectangle.

Add all four side lengths.
2 × (9+9) = 36.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 36 cm

Worked Example 3

Problem: Find the perimeter of a 6 cm by 4 cm rectangle.

Add all four side lengths.
2 × (6+4) = 20.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 20 cm

Worked Example 4

Problem: Find the perimeter of a 12 cm by 5 cm rectangle.

Add all four side lengths.
2 × (12+5) = 34.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 34 cm

Worked Example 5

Problem: Find the perimeter of a 12 cm by 2 cm rectangle.

Add all four side lengths.
2 × (12+2) = 28.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 28 cm

Worked Example 6

Problem: Find the perimeter of a 6 cm by 2 cm rectangle.

Add all four side lengths.
2 × (6+2) = 16.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 16 cm

Worked Example 7

Problem: Find the perimeter of a 6 cm by 8 cm rectangle.

Add all four side lengths.
2 × (6+8) = 28.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 28 cm

Worked Example 8

Problem: Find the perimeter of a 8 cm by 3 cm rectangle.

Add all four side lengths.
2 × (8+3) = 22.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 22 cm

Worked Example 9

Problem: Find the perimeter of a 10 cm by 9 cm rectangle.

Add all four side lengths.
2 × (10+9) = 38.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 38 cm

Worked Example 10

Problem: Find the perimeter of a 8 cm by 9 cm rectangle.

Add all four side lengths.
2 × (8+9) = 34.

Very beginner explanation: Perimeter is the distance around a shape.

Answer: 34 cm

Practice Exercise

Create and solve one new example of Perimeter versus area. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

55.12 Real-life rectangle problems

Beginner Explanation

First identify what is given and what must be found. Then choose a strategy, show the steps clearly, and check the final answer.

10 Worked Examples with Answers

Worked Example 1

Problem: Find the area of a 7 cm by 8 cm rectangle.

Use area = length × width.
7 × 8 = 56.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 56 cm²

Worked Example 2

Problem: Find the area of a 8 cm by 9 cm rectangle.

Use area = length × width.
8 × 9 = 72.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 72 cm²

Worked Example 3

Problem: Find the area of a 6 cm by 9 cm rectangle.

Use area = length × width.
6 × 9 = 54.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 54 cm²

Worked Example 4

Problem: Find the area of a 7 cm by 7 cm rectangle.

Use area = length × width.
7 × 7 = 49.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 49 cm²

Worked Example 5

Problem: Find the area of a 6 cm by 6 cm rectangle.

Use area = length × width.
6 × 6 = 36.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 36 cm²

Worked Example 6

Problem: Find the area of a 5 cm by 6 cm rectangle.

Use area = length × width.
5 × 6 = 30.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 30 cm²

Worked Example 7

Problem: Find the area of a 11 cm by 9 cm rectangle.

Use area = length × width.
11 × 9 = 99.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 99 cm²

Worked Example 8

Problem: Find the area of a 9 cm by 9 cm rectangle.

Use area = length × width.
9 × 9 = 81.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 81 cm²

Worked Example 9

Problem: Find the area of a 11 cm by 4 cm rectangle.

Use area = length × width.
11 × 4 = 44.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 44 cm²

Worked Example 10

Problem: Find the area of a 4 cm by 6 cm rectangle.

Use area = length × width.
4 × 6 = 24.

Very beginner explanation: Area measures the surface inside a 2D shape.

Answer: 24 cm²

Practice Exercise

Create and solve one new example of Real-life rectangle problems. Show the steps and explain how you checked it.

Common Mistake

Do not rush into a calculation before understanding the question. Check place values, labels, units, and whether your answer fits the situation.

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30 Review Questions and Answers

Q1. What is important to understand about Meaning of perimeter?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q2. What is important to understand about Perimeter of a rectangle?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q3. What is important to understand about Perimeter of a square?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q4. What is important to understand about Missing side from perimeter?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q5. What is important to understand about Meaning of area?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q6. What is important to understand about Square units?

Answer: Square units is an important Grade 4 mathematics idea in Perimeter and Rectangle Area. Understand the meaning first, then use a clear representation or strategy and check whether the answer makes sense.

Q7. What is important to understand about Area of a rectangle?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q8. What is important to understand about Area of a square?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q9. What is important to understand about Connecting arrays and area?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q10. What is important to understand about Finding a missing side from area?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q11. What is important to understand about Perimeter versus area?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q12. What is important to understand about Real-life rectangle problems?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q13. How would you explain Meaning of perimeter?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q14. How would you explain Perimeter of a rectangle?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q15. How would you explain Perimeter of a square?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q16. How would you explain Missing side from perimeter?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q17. How would you explain Meaning of area?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q18. How would you explain Square units?

Q19. How would you explain Area of a rectangle?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q20. How would you explain Area of a square?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q21. How would you explain Connecting arrays and area?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q22. How would you explain Finding a missing side from area?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q23. How would you explain Perimeter versus area?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q24. How would you explain Real-life rectangle problems?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q25. What should a beginner check when working with Meaning of perimeter?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q26. What should a beginner check when working with Perimeter of a rectangle?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q27. What should a beginner check when working with Perimeter of a square?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q28. What should a beginner check when working with Missing side from perimeter?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.

Q29. What should a beginner check when working with Meaning of area?

Answer: Spatial reasoning uses shape, position, movement, and measurement. Diagrams, coordinates, and measurements make relationships easier to see.