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9th Grade Circumference and Area of Circles Worksheet — Level 2 — Practice Set 2 — Answers

Answer sheet with worked solutions for the 9th Grade area & perimeter worksheet.

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Success TutoringWorksheetsAnswer sheet9th Grade · Mathematics · Area & Perimeter

9th Grade Circumference and Area of Circles Worksheet — Level 2 — Practice Set 2 — 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 36 cm. Find its area, correct to 1 decimal place.

Answer: 1017.9 cm2

  1. r = 36 ÷ 2 = 18 cm
  2. A = π × r2 = π × 182 = π × 324
  3. ≈ 1017.9 cm2
2.Find the area of a semicircle with a radius of 16 cm, correct to 1 decimal place.

Answer: 402.1 cm2

  1. A = ½ × π × r2 = ½ × π × 256
  2. ≈ 402.1 cm2
3.A circle has a radius of 8 cm. Find its area, correct to 1 decimal place.

Answer: 201.1 cm2

  1. A = π × r2 = π × 82 = π × 64
  2. ≈ 201.1 cm2
4.A circle has a diameter of 18 cm. Find its area, correct to 1 decimal place.

Answer: 254.5 cm2

  1. r = 18 ÷ 2 = 9 cm
  2. A = π × r2 = π × 92 = π × 81
  3. ≈ 254.5 cm2
5.A circle has a diameter of 40 cm. Find its area, correct to 1 decimal place.

Answer: 1256.6 cm2

  1. r = 40 ÷ 2 = 20 cm
  2. A = π × r2 = π × 202 = π × 400
  3. ≈ 1256.6 cm2
6.A circle has a diameter of 34 cm. Find its circumference, correct to 1 decimal place.

Answer: 106.8 cm

  1. C = π × d = π × 34
  2. ≈ 106.8 cm
7.A circle has a diameter of 24 cm. Find its circumference, correct to 1 decimal place.

Answer: 75.4 cm

  1. C = π × d = π × 24
  2. ≈ 75.4 cm
8.A circle has a diameter of 4 cm. Find its circumference, correct to 1 decimal place.

Answer: 12.6 cm

  1. C = π × d = π × 4
  2. ≈ 12.6 cm
9.A circle has a diameter of 20 cm. Find its area, correct to 1 decimal place.

Answer: 314.2 cm2

  1. r = 20 ÷ 2 = 10 cm
  2. A = π × r2 = π × 102 = π × 100
  3. ≈ 314.2 cm2
10.Find the area of a semicircle with a radius of 2 cm, correct to 1 decimal place.

Answer: 6.3 cm2

  1. A = ½ × π × r2 = ½ × π × 4
  2. ≈ 6.3 cm2
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