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 diameter of 4 cm. Find its area, correct to 1 decimal place.
Answer: 12.6 cm2
- r = 4 ÷ 2 = 2 cm
- A = π × r2 = π × 22 = π × 4
- ≈ 12.6 cm2
2.A circle has a radius of 16 cm. What is its diameter?
Answer: 32 cm
The diameter is twice the radius.
3.A circle has a diameter of 4 cm. What is its radius?
Answer: 2 cm
The radius is half the diameter.
4.A circle has a radius of 19 cm. What is its diameter?
Answer: 38 cm
The diameter is twice the radius.
5.A circle has a radius of 5 cm. What is its diameter?
Answer: 10 cm
The diameter is twice the radius.
6.A circle has a radius of 4 cm. Find its area, correct to 1 decimal place.
Answer: 50.3 cm2
- A = π × r2 = π × 42 = π × 16
- ≈ 50.3 cm2
7.A circle has a diameter of 32 cm. Find its circumference, correct to 1 decimal place.
Answer: 100.5 cm
- C = π × d = π × 32
- ≈ 100.5 cm
8.A circle has a diameter of 36 cm. What is its radius?
Answer: 18 cm
The radius is half the diameter.
9.A circle has a diameter of 12 cm. Find its area, correct to 1 decimal place.
Answer: 113.1 cm2
- r = 12 ÷ 2 = 6 cm
- A = π × r2 = π × 62 = π × 36
- ≈ 113.1 cm2
10.A circle has a radius of 18 cm. What is its diameter?
Answer: 36 cm
The diameter is twice the radius.
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