Year 9 Circumference and Area of Circles Worksheet — Level 2 — Practice Set 4 — 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 2 — 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 radius of 17 cm. Find its circumference, correct to 1 decimal place.
Answer: 106.8 cm
- C = 2 × π × r = 2 × π × 17
- ≈ 106.8 cm
2.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
3.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
4.A circle has a radius of 14 cm. Find its circumference, correct to 1 decimal place.
Answer: 88.0 cm
- C = 2 × π × r = 2 × π × 14
- ≈ 88.0 cm
5.A circle has a radius of 2 cm. Find its circumference, correct to 1 decimal place.
Answer: 12.6 cm
- C = 2 × π × r = 2 × π × 2
- ≈ 12.6 cm
6.Find the area of a semicircle with a radius of 20 cm, correct to 1 decimal place.
Answer: 628.3 cm2
- A = ½ × π × r2 = ½ × π × 400
- ≈ 628.3 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 20 cm. Find its circumference, correct to 1 decimal place.
Answer: 62.8 cm
- C = π × d = π × 20
- ≈ 62.8 cm
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.Find the area of a semicircle with a radius of 13 cm, correct to 1 decimal place.
Answer: 265.5 cm2
- A = ½ × π × r2 = ½ × π × 169
- ≈ 265.5 cm2
Marking tips
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