MathsAges 16-18

Circle circumference & area

Use π ≈ 3.14 and radius r to calculate the circumference or area of a circle. Review suitability for your learners before teaching.

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Age band:Ages 13-15 Ages 16-18

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Worksheet StudioPractice pack · Ages 16-18

Circle circumference & area

Take your time. Show your thinking.

1. A circle has radius 18 cm. Using π = 3.14, find its circumference.
18 cm · 3.14 · Circle circumference & area
2. A circle has radius 2 cm. Using π = 3.14, find its area.
2 cm · 3.14 · Circle circumference & area
3. A circle has radius 17 cm. Using π = 3.14, find its area.
17 cm · 3.14 · Circle circumference & area
4. A circle has radius 2 cm. Using π = 3.14, find its circumference.
2 cm · 3.14 · Circle circumference & area
5. A circle has radius 3 cm. Using π = 3.14, find its circumference.
3 cm · 3.14 · Circle circumference & area
6. A circle has radius 17 cm. Using π = 3.14, find its circumference.
17 cm · 3.14 · Circle circumference & area
7. A circle has radius 6 cm. Using π = 3.14, find its area.
6 cm · 3.14 · Circle circumference & area
8. A circle has radius 20 cm. Using π = 3.14, find its area.
20 cm · 3.14 · Circle circumference & area
9. A circle has radius 9 cm. Using π = 3.14, find its circumference.
9 cm · 3.14 · Circle circumference & area
10. A circle has radius 19 cm. Using π = 3.14, find its area.
19 cm · 3.14 · Circle circumference & area
11. A circle has radius 13 cm. Using π = 3.14, find its circumference.
13 cm · 3.14 · Circle circumference & area
12. A circle has radius 6 cm. Using π = 3.14, find its circumference.
6 cm · 3.14 · Circle circumference & area

12 questions · Seed 45 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 16-18

Circle circumference & area

Answers and reasoning. Review before teaching.

1. A circle has radius 18 cm. Using π = 3.14, find its circumference.
113.04 cm
Circumference C = 2πr = 2 × 3.14 × 18 = 113.04 cm.
2. A circle has radius 2 cm. Using π = 3.14, find its area.
12.56 cm²
Area A = πr² = 3.14 × 2² = 12.56 cm².
3. A circle has radius 17 cm. Using π = 3.14, find its area.
907.46 cm²
Area A = πr² = 3.14 × 17² = 907.46 cm².
4. A circle has radius 2 cm. Using π = 3.14, find its circumference.
12.56 cm
Circumference C = 2πr = 2 × 3.14 × 2 = 12.56 cm.
5. A circle has radius 3 cm. Using π = 3.14, find its circumference.
18.84 cm
Circumference C = 2πr = 2 × 3.14 × 3 = 18.84 cm.
6. A circle has radius 17 cm. Using π = 3.14, find its circumference.
106.76 cm
Circumference C = 2πr = 2 × 3.14 × 17 = 106.76 cm.
7. A circle has radius 6 cm. Using π = 3.14, find its area.
113.04 cm²
Area A = πr² = 3.14 × 6² = 113.04 cm².
8. A circle has radius 20 cm. Using π = 3.14, find its area.
1256 cm²
Area A = πr² = 3.14 × 20² = 1256 cm².
9. A circle has radius 9 cm. Using π = 3.14, find its circumference.
56.52 cm
Circumference C = 2πr = 2 × 3.14 × 9 = 56.52 cm.
10. A circle has radius 19 cm. Using π = 3.14, find its area.
1133.54 cm²
Area A = πr² = 3.14 × 19² = 1133.54 cm².
11. A circle has radius 13 cm. Using π = 3.14, find its circumference.
81.64 cm
Circumference C = 2πr = 2 × 3.14 × 13 = 81.64 cm.
12. A circle has radius 6 cm. Using π = 3.14, find its circumference.
37.68 cm
Circumference C = 2πr = 2 × 3.14 × 6 = 37.68 cm.

12 questions · Seed 45 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 16-18

Circle circumference & area

Take your time. Show your thinking.

1. A circle has radius 18 cm. Using π = 3.14, find its circumference.
18 cm · 3.14 · Circle circumference & area
2. A circle has radius 2 cm. Using π = 3.14, find its area.
2 cm · 3.14 · Circle circumference & area
3. A circle has radius 17 cm. Using π = 3.14, find its area.
17 cm · 3.14 · Circle circumference & area
4. A circle has radius 2 cm. Using π = 3.14, find its circumference.
2 cm · 3.14 · Circle circumference & area
5. A circle has radius 3 cm. Using π = 3.14, find its circumference.
3 cm · 3.14 · Circle circumference & area
6. A circle has radius 17 cm. Using π = 3.14, find its circumference.
17 cm · 3.14 · Circle circumference & area
7. A circle has radius 6 cm. Using π = 3.14, find its area.
6 cm · 3.14 · Circle circumference & area
8. A circle has radius 20 cm. Using π = 3.14, find its area.
20 cm · 3.14 · Circle circumference & area
9. A circle has radius 9 cm. Using π = 3.14, find its circumference.
9 cm · 3.14 · Circle circumference & area
10. A circle has radius 19 cm. Using π = 3.14, find its area.
19 cm · 3.14 · Circle circumference & area
11. A circle has radius 13 cm. Using π = 3.14, find its circumference.
13 cm · 3.14 · Circle circumference & area
12. A circle has radius 6 cm. Using π = 3.14, find its circumference.
6 cm · 3.14 · Circle circumference & area

12 questions · Seed 45 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 16-18

Circle circumference & area

Answers and reasoning. Review before teaching.

1. A circle has radius 18 cm. Using π = 3.14, find its circumference.
113.04 cm
Circumference C = 2πr = 2 × 3.14 × 18 = 113.04 cm.
2. A circle has radius 2 cm. Using π = 3.14, find its area.
12.56 cm²
Area A = πr² = 3.14 × 2² = 12.56 cm².
3. A circle has radius 17 cm. Using π = 3.14, find its area.
907.46 cm²
Area A = πr² = 3.14 × 17² = 907.46 cm².
4. A circle has radius 2 cm. Using π = 3.14, find its circumference.
12.56 cm
Circumference C = 2πr = 2 × 3.14 × 2 = 12.56 cm.
5. A circle has radius 3 cm. Using π = 3.14, find its circumference.
18.84 cm
Circumference C = 2πr = 2 × 3.14 × 3 = 18.84 cm.
6. A circle has radius 17 cm. Using π = 3.14, find its circumference.
106.76 cm
Circumference C = 2πr = 2 × 3.14 × 17 = 106.76 cm.
7. A circle has radius 6 cm. Using π = 3.14, find its area.
113.04 cm²
Area A = πr² = 3.14 × 6² = 113.04 cm².
8. A circle has radius 20 cm. Using π = 3.14, find its area.
1256 cm²
Area A = πr² = 3.14 × 20² = 1256 cm².
9. A circle has radius 9 cm. Using π = 3.14, find its circumference.
56.52 cm
Circumference C = 2πr = 2 × 3.14 × 9 = 56.52 cm.
10. A circle has radius 19 cm. Using π = 3.14, find its area.
1133.54 cm²
Area A = πr² = 3.14 × 19² = 1133.54 cm².
11. A circle has radius 13 cm. Using π = 3.14, find its circumference.
81.64 cm
Circumference C = 2πr = 2 × 3.14 × 13 = 81.64 cm.
12. A circle has radius 6 cm. Using π = 3.14, find its circumference.
37.68 cm
Circumference C = 2πr = 2 × 3.14 × 6 = 37.68 cm.

12 questions · Seed 45 · Age guidance, not curriculum certification