Year 9 Circumference and Area of Circles Worksheet — Level 1 — Answers
Answer sheet with worked solutions for the Year 9 area & perimeter worksheet.
Success TutoringWorksheetsAnswer sheetYear 9 · Mathematics · Area & PerimeterYear 9 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 15 cm. Find its circumference, correct to 1 decimal place.
Answer: 94.2 cm
- C = 2 × π × r = 2 × π × 15
- ≈ 94.2 cm
3.A circle has a radius of 18 cm. What is its diameter?
Answer: 36 cm
The diameter is twice the radius.
4.A circle has a diameter of 26 cm. What is its radius?
Answer: 13 cm
The radius is half the diameter.
5.A circle has a diameter of 22 cm. Find its circumference, correct to 1 decimal place.
Answer: 69.1 cm
- C = π × d = π × 22
- ≈ 69.1 cm
6.A circle has a radius of 6 cm. What is its diameter?
Answer: 12 cm
The diameter is twice the radius.
7.A circle has a radius of 3 cm. Find its circumference, correct to 1 decimal place.
Answer: 18.8 cm
- C = 2 × π × r = 2 × π × 3
- ≈ 18.8 cm
8.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
9.A circle has a radius of 14 cm. Find its area, correct to 1 decimal place.
Answer: 615.8 cm2
- A = π × r2 = π × 142 = π × 196
- ≈ 615.8 cm2
10.A circle has a radius of 4 cm. What is its diameter?
Answer: 8 cm
The diameter is twice the radius.
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