Year 9 Circumference and Area of Circles Worksheet — Level 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 — Answers
Show your working. Use the π button on your calculator and round to 1 decimal place unless told otherwise.
1.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
2.A circle has a radius of 15 cm. Find its area, correct to 1 decimal place.
Answer: 706.9 cm2
- A = π × r2 = π × 152 = π × 225
- ≈ 706.9 cm2
3.Find the area of a semicircle with a radius of 7 cm, correct to 1 decimal place.
Answer: 77.0 cm2
- A = ½ × π × r2 = ½ × π × 49
- ≈ 77.0 cm2
4.A circle has a diameter of 16 cm. Find its area, correct to 1 decimal place.
Answer: 201.1 cm2
- r = 16 ÷ 2 = 8 cm
- A = π × r2 = π × 82 = π × 64
- ≈ 201.1 cm2
5.A circle has a radius of 20 cm. Find its area, correct to 1 decimal place.
Answer: 1256.6 cm2
- A = π × r2 = π × 202 = π × 400
- ≈ 1256.6 cm2
6.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
7.A circle has a diameter of 34 cm. Find its area, correct to 1 decimal place.
Answer: 907.9 cm2
- r = 34 ÷ 2 = 17 cm
- A = π × r2 = π × 172 = π × 289
- ≈ 907.9 cm2
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 10 cm. Find its circumference, correct to 1 decimal place.
Answer: 31.4 cm
- C = π × d = π × 10
- ≈ 31.4 cm
10.A circle has a radius of 11 cm. Find its area, correct to 1 decimal place.
Answer: 380.1 cm2
- A = π × r2 = π × 112 = π × 121
- ≈ 380.1 cm2
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