8th Grade Circumference and Area of Circles Worksheet — Level 2 — Practice Set 4 — Answers
Answer sheet with worked solutions for the 8th Grade area & perimeter worksheet.
Success TutoringWorksheetsAnswer sheet8th Grade · Mathematics · Area & Perimeter8th Grade Circumference and Area of Circles Worksheet — Level 2 — Practice Set 4 — Answers
Show your work. 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 circumference, correct to 1 decimal place.
Answer: 75.4 cm
- C = π × d = π × 24
- ≈ 75.4 cm
2.A circle has a diameter of 30 cm. Find its circumference, correct to 1 decimal place.
Answer: 94.2 cm
- C = π × d = π × 30
- ≈ 94.2 cm
3.Find the area of a semicircle with a radius of 12 cm, correct to 1 decimal place.
Answer: 226.2 cm2
- A = ½ × π × r2 = ½ × π × 144
- ≈ 226.2 cm2
4.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
5.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
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.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
8.Find the area of a semicircle with a radius of 15 cm, correct to 1 decimal place.
Answer: 353.4 cm2
- A = ½ × π × r2 = ½ × π × 225
- ≈ 353.4 cm2
9.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
10.A circle has a radius of 18 cm. Find its area, correct to 1 decimal place.
Answer: 1017.9 cm2
- A = π × r2 = π × 182 = π × 324
- ≈ 1017.9 cm2
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