Year 9 Circumference and Area of Circles Worksheet — Level 2 — Practice Set 2 — 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 2 — 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 24 cm. Find its area, correct to 1 decimal place.
Answer: 452.4 cm2
- r = 24 ÷ 2 = 12 cm
- A = π × r2 = π × 122 = π × 144
- ≈ 452.4 cm2
2.A circle has a radius of 12 cm. Find its area, correct to 1 decimal place.
Answer: 452.4 cm2
- A = π × r2 = π × 122 = π × 144
- ≈ 452.4 cm2
3.A circle has a diameter of 18 cm. Find its circumference, correct to 1 decimal place.
Answer: 56.5 cm
- C = π × d = π × 18
- ≈ 56.5 cm
4.A circle has a diameter of 8 cm. Find its circumference, correct to 1 decimal place.
Answer: 25.1 cm
- C = π × d = π × 8
- ≈ 25.1 cm
5.Find the area of a semicircle with a radius of 14 cm, correct to 1 decimal place.
Answer: 307.9 cm2
- A = ½ × π × r2 = ½ × π × 196
- ≈ 307.9 cm2
6.A circle has a diameter of 20 cm. Find its area, correct to 1 decimal place.
Answer: 314.2 cm2
- r = 20 ÷ 2 = 10 cm
- A = π × r2 = π × 102 = π × 100
- ≈ 314.2 cm2
7.A circle has a diameter of 4 cm. Find its circumference, correct to 1 decimal place.
Answer: 12.6 cm
- C = π × d = π × 4
- ≈ 12.6 cm
8.Find the area of a semicircle with a radius of 4 cm, correct to 1 decimal place.
Answer: 25.1 cm2
- A = ½ × π × r2 = ½ × π × 16
- ≈ 25.1 cm2
9.A circle has a diameter of 40 cm. Find its area, correct to 1 decimal place.
Answer: 1256.6 cm2
- r = 40 ÷ 2 = 20 cm
- A = π × r2 = π × 202 = π × 400
- ≈ 1256.6 cm2
10.Find the area of a semicircle with a radius of 5 cm, correct to 1 decimal place.
Answer: 39.3 cm2
- A = ½ × π × r2 = ½ × π × 25
- ≈ 39.3 cm2
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