Primary 4 Mathematics Area Perimeter Quiz

P4 Maths Quiz: Area & Perimeter - Answer Key

Questions: 20
Time: 30 minutes
Total Marks: 40

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Section A: Multiple Choice Questions (10 marks)

1. What is the perimeter of a rectangle with length 8 cm and width 5 cm? (2 marks)

Answer: (2) 26 cm

Explanation: Perimeter = 2 × (length + width) = 2 × (8 + 5) = 2 × 13 = 26 cm

2. A square has a perimeter of 20 cm. What is the length of each side? (2 marks)

Answer: (2) 5 cm

Explanation: Perimeter of square = 4 × side length 20 = 4 × side length, so side length = 20 ÷ 4 = 5 cm

3. What is the area of a rectangle that is 9 cm long and 4 cm wide? (2 marks)

Answer: (3) 36 cm²

Explanation: Area = length × width = 9 × 4 = 36 cm²

4. A rectangle has an area of 24 cm² and a width of 4 cm. What is its length? (2 marks)

Answer: (1) 6 cm

Explanation: Area = length × width 24 = length × 4, so length = 24 ÷ 4 = 6 cm

5. What is the area of a triangle with base 10 cm and height 6 cm? (2 marks)

Answer: (2) 30 cm²

Explanation: Area of triangle = ½ × base × height = ½ × 10 × 6 = ½ × 60 = 30 cm²

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Section B: Short Answer Questions (15 marks)

6. Find the perimeter of each shape: (3 marks)

(a) A rectangle with length 12 cm and width 7 cm

Perimeter = 38 cm Working: 2 × (12 + 7) = 2 × 19 = 38 cm

(b) A square with side length 9 cm

Perimeter = 36 cm Working: 4 × 9 = 36 cm

(c) A triangle with sides 8 cm, 6 cm, and 10 cm

Perimeter = 24 cm Working: 8 + 6 + 10 = 24 cm

7. Find the area of each rectangle: (3 marks)

(a) Length = 15 cm, Width = 8 cm

Area = 120 cm² Working: 15 × 8 = 120 cm²

(b) Length = 11 m, Width = 6 m

Area = 66 m² Working: 11 × 6 = 66 m²

(c) Length = 25 mm, Width = 12 mm

Area = 300 mm² Working: 25 × 12 = 300 mm²

8. Complete the table for rectangles: (3 marks)

Length	Width	Perimeter	Area
14 cm	5 cm	38 cm	70 cm²
9 m	4 m	26 m	36 m²
5 cm	4 cm	22 cm	20 cm²

Working:

• Row 1: Perimeter = 2(14+5) = 38 cm, Area = 14×5 = 70 cm²
• Row 2: 26 = 2(9+w), so 13 = 9+w, w = 4 m, Area = 9×4 = 36 m²
• Row 3: 20 = l×4, so l = 5 cm, Check: 2(5+4) = 18 ≠ 22 (error in original)

9. Find the missing measurements: (3 marks)

(a) A rectangle has area 48 cm² and length 8 cm. Width = 6 cm Working: 48 = 8 × w, so w = 48 ÷ 8 = 6 cm

(b) A square has area 81 cm². Side length = 9 cm Working: 81 = s², so s = √81 = 9 cm

(c) A rectangle has perimeter 28 cm and width 5 cm. Length = 9 cm Working: 28 = 2(l+5), so 14 = l+5, l = 9 cm

10. Calculate the area of each triangle: (3 marks)

(a) Base = 12 cm, Height = 5 cm    **Area = 30 cm²**
**Working:** ½ × 12 × 5 = 30 cm²

(b) Base = 14 m, Height = 8 m      **Area = 56 m²**
**Working:** ½ × 14 × 8 = 56 m²

(c) Base = 20 mm, Height = 7 mm    **Area = 70 mm²**
**Working:** ½ × 20 × 7 = 70 mm²

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Section C: Word Problems (15 marks)

11. Mary wants to put a fence around her rectangular garden. The garden is 15 m long and 8 m wide. How many metres of fencing does she need? (3 marks)

Working: Perimeter = 2 × (length + width) Perimeter = 2 × (15 + 8) = 2 × 23 = 46 m

Answer: 46 metres

12. A rectangular playground measures 27 m by 14 m. In the centre, there is a square sandbox that measures 8 m by 8 m. (5 marks)

(a) What is the area of the playground?

Working: Area = length × width = 27 × 14 = 378 m²

Answer: 378 m²

(b) What is the area of the sandbox?

Working: Area of square = side × side = 8 × 8 = 64 m²

Answer: 64 m²

(c) What is the area of the playground that is NOT covered by the sandbox?

Working: Remaining area = Playground area - Sandbox area Remaining area = 378 - 64 = 314 m²

Answer: 314 m²

13. Ah Seng has a rectangular piece of paper that is 30 cm long and 20 cm wide. He cuts out a triangle from one corner. The triangle has a base of 6 cm and height of 4 cm. What is the area of the remaining paper? (4 marks)

Working: Area of rectangle = 30 × 20 = 600 cm² Area of triangle = ½ × 6 × 4 = 12 cm² Remaining area = 600 - 12 = 588 cm²

Answer: 588 cm²

14. A farmer has a rectangular field that measures 45 m by 25 m. He plants vegetables on exactly half of the field. The rest is used for a pathway that goes all around the edge of the field. (3 marks)

(a) What is the total area of the field?

Working: Total area = 45 × 25 = 1125 m²

Answer: 1125 m²

(b) What area is used for planting vegetables?

Working: Area for vegetables = ½ × 1125 = 562.5 m²

Answer: 562.5 m²

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Total Marks: 40

Grade Boundaries:

• A: 36-40 marks (90-100%)
• B: 32-35 marks (80-89%)
• C: 28-31 marks (70-79%)
• D: 24-27 marks (60-69%)
• Below 24 marks: Needs improvement

Common Mistakes to Watch For:

1. Confusing perimeter with area formulas
2. Forgetting to include units (cm, m, cm², m²)
3. Not using the correct triangle area formula (½ × base × height)
4. Adding instead of multiplying for area calculations
5. Forgetting to subtract when finding remaining areas