8th Grade Circumference and Area of Circles Worksheet — Level 1 — 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 1 — 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 radius of 16 cm. Find its circumference, correct to 1 decimal place.
Answer: 100.5 cm
- C = 2 × π × r = 2 × π × 16
- ≈ 100.5 cm
2.A circle has a diameter of 38 cm. Find its circumference, correct to 1 decimal place.
Answer: 119.4 cm
- C = π × d = π × 38
- ≈ 119.4 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 20 cm. Find its area, correct to 1 decimal place.
Answer: 1256.6 cm2
- A = π × r2 = π × 202 = π × 400
- ≈ 1256.6 cm2
5.A circle has a diameter of 8 cm. What is its radius?
Answer: 4 cm
The radius is half the diameter.
6.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
7.A circle has a radius of 11 cm. Find its circumference, correct to 1 decimal place.
Answer: 69.1 cm
- C = 2 × π × r = 2 × π × 11
- ≈ 69.1 cm
8.A circle has a diameter of 10 cm. What is its radius?
Answer: 5 cm
The radius is half the diameter.
9.A circle has a diameter of 40 cm. What is its radius?
Answer: 20 cm
The radius is half the diameter.
10.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
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