Year 8 Circumference and Area of Circles Worksheet — Level 1 — Answers
Answer sheet with worked solutions for the Year 8 area & perimeter worksheet.
Success TutoringWorksheetsAnswer sheetYear 8 · Mathematics · Area & PerimeterYear 8 Circumference and Area of Circles Worksheet — Level 1 — 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 radius of 9 cm. What is its diameter?
Answer: 18 cm
The diameter is twice the radius.
2.A circle has a radius of 7 cm. Find its area, correct to 1 decimal place.
Answer: 153.9 cm2
- A = π × r2 = π × 72 = π × 49
- ≈ 153.9 cm2
3.A circle has a diameter of 10 cm. Find its area, correct to 1 decimal place.
Answer: 78.5 cm2
- r = 10 ÷ 2 = 5 cm
- A = π × r2 = π × 52 = π × 25
- ≈ 78.5 cm2
4.A circle has a diameter of 22 cm. What is its radius?
Answer: 11 cm
The radius is half the diameter.
5.A circle has a radius of 15 cm. What is its diameter?
Answer: 30 cm
The diameter is twice the radius.
6.A circle has a radius of 19 cm. What is its diameter?
Answer: 38 cm
The diameter is twice the radius.
7.A circle has a diameter of 16 cm. Find its circumference, correct to 1 decimal place.
Answer: 50.3 cm
- C = π × d = π × 16
- ≈ 50.3 cm
8.A circle has a diameter of 18 cm. Find its area, correct to 1 decimal place.
Answer: 254.5 cm2
- r = 18 ÷ 2 = 9 cm
- A = π × r2 = π × 92 = π × 81
- ≈ 254.5 cm2
9.A circle has a radius of 17 cm. Find its area, correct to 1 decimal place.
Answer: 907.9 cm2
- A = π × r2 = π × 172 = π × 289
- ≈ 907.9 cm2
10.A circle has a radius of 9 cm. Find its circumference, correct to 1 decimal place.
Answer: 56.5 cm
- C = 2 × π × r = 2 × π × 9
- ≈ 56.5 cm
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