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 5 cm. What is its diameter?
Answer: 10 cm
The diameter is twice the radius.
2.A circle has a diameter of 12 cm. What is its radius?
Answer: 6 cm
The radius is half the diameter.
3.A circle has a diameter of 8 cm. What is its radius?
Answer: 4 cm
The radius is half the diameter.
4.A circle has a radius of 19 cm. Find its area, correct to 1 decimal place.
Answer: 1134.1 cm2
- A = π × r2 = π × 192 = π × 361
- ≈ 1134.1 cm2
5.A circle has a radius of 12 cm. Find its circumference, correct to 1 decimal place.
Answer: 75.4 cm
- C = 2 × π × r = 2 × π × 12
- ≈ 75.4 cm
6.A circle has a diameter of 34 cm. Find its circumference, correct to 1 decimal place.
Answer: 106.8 cm
- C = π × d = π × 34
- ≈ 106.8 cm
7.A circle has a diameter of 22 cm. What is its radius?
Answer: 11 cm
The radius is half the diameter.
8.A circle has a radius of 7 cm. Find its circumference, correct to 1 decimal place.
Answer: 44.0 cm
- C = 2 × π × r = 2 × π × 7
- ≈ 44.0 cm
9.A circle has a radius of 6 cm. What is its diameter?
Answer: 12 cm
The diameter is twice the radius.
10.A circle has a diameter of 6 cm. Find its area, correct to 1 decimal place.
Answer: 28.3 cm2
- r = 6 ÷ 2 = 3 cm
- A = π × r2 = π × 32 = π × 9
- ≈ 28.3 cm2
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