Year 7 Circumference and Area of Circles Worksheet — Level 1 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 7 area & perimeter worksheet.
Success TutoringWorksheetsAnswer sheetYear 7 · Mathematics · Area & PerimeterYear 7 Circumference and Area of Circles Worksheet — Level 1 — Practice Set 4 — Answers
Show your working. Use the π button on your calculator and round to 1 decimal place unless told otherwise.
1.A circle has a diameter of 16 cm. What is its radius?
Answer: 8 cm
The radius is half the diameter.
2.A circle has a radius of 20 cm. Find its area, correct to 1 decimal place.
Answer: 1256.6 cm2
- A = π × r2 = π × 202 = π × 400
- ≈ 1256.6 cm2
3.A circle has a radius of 13 cm. Find its area, correct to 1 decimal place.
Answer: 530.9 cm2
- A = π × r2 = π × 132 = π × 169
- ≈ 530.9 cm2
4.A circle has a radius of 10 cm. What is its diameter?
Answer: 20 cm
The diameter is twice the radius.
5.A circle has a diameter of 20 cm. Find its area, correct to 1 decimal place.
Answer: 314.2 cm2
- r = 20 ÷ 2 = 10 cm
- A = π × r2 = π × 102 = π × 100
- ≈ 314.2 cm2
6.A circle has a diameter of 32 cm. Find its area, correct to 1 decimal place.
Answer: 804.2 cm2
- r = 32 ÷ 2 = 16 cm
- A = π × r2 = π × 162 = π × 256
- ≈ 804.2 cm2
7.A circle has a radius of 20 cm. What is its diameter?
Answer: 40 cm
The diameter is twice the radius.
8.A circle has a radius of 17 cm. What is its diameter?
Answer: 34 cm
The diameter is twice the radius.
9.A circle has a diameter of 40 cm. What is its radius?
Answer: 20 cm
The radius is half the diameter.
10.A circle has a diameter of 6 cm. What is its radius?
Answer: 3 cm
The radius is half the diameter.
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