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 3 cm. Using π = 3.14, find its area.
3 cm · 3.14 · Circle circumference & area
2. A circle has radius 7 cm. Using π = 3.14, find its area.
7 cm · 3.14 · Circle circumference & area
3. A circle has radius 16 cm. Using π = 3.14, find its circumference.
16 cm · 3.14 · Circle circumference & area
4. A circle has radius 17 cm. Using π = 3.14, find its area.
17 cm · 3.14 · Circle circumference & area
5. A circle has radius 18 cm. Using π = 3.14, find its area.
18 cm · 3.14 · Circle circumference & area
6. A circle has radius 5 cm. Using π = 3.14, find its area.
5 cm · 3.14 · Circle circumference & area
7. A circle has radius 15 cm. Using π = 3.14, find its area.
15 cm · 3.14 · Circle circumference & area
8. A circle has radius 8 cm. Using π = 3.14, find its area.
8 cm · 3.14 · Circle circumference & area
9. A circle has radius 6 cm. Using π = 3.14, find its area.
6 cm · 3.14 · Circle circumference & area
10. A circle has radius 20 cm. Using π = 3.14, find its area.
20 cm · 3.14 · Circle circumference & area
11. A circle has radius 11 cm. Using π = 3.14, find its circumference.
11 cm · 3.14 · Circle circumference & area
12. A circle has radius 8 cm. Using π = 3.14, find its circumference.
8 cm · 3.14 · Circle circumference & area

12 questions · Seed 57 · 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 3 cm. Using π = 3.14, find its area.
28.26 cm²
Area A = πr² = 3.14 × 3² = 28.26 cm².
2. A circle has radius 7 cm. Using π = 3.14, find its area.
153.86 cm²
Area A = πr² = 3.14 × 7² = 153.86 cm².
3. A circle has radius 16 cm. Using π = 3.14, find its circumference.
100.48 cm
Circumference C = 2πr = 2 × 3.14 × 16 = 100.48 cm.
4. 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.
5. A circle has radius 18 cm. Using π = 3.14, find its area.
1017.36 cm²
Area A = πr² = 3.14 × 18² = 1017.36 cm².
6. A circle has radius 5 cm. Using π = 3.14, find its area.
78.5 cm²
Area A = πr² = 3.14 × 5² = 78.5 cm².
7. A circle has radius 15 cm. Using π = 3.14, find its area.
706.5 cm²
Area A = πr² = 3.14 × 15² = 706.5 cm².
8. A circle has radius 8 cm. Using π = 3.14, find its area.
200.96 cm²
Area A = πr² = 3.14 × 8² = 200.96 cm².
9. 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.
10. A circle has radius 20 cm. Using π = 3.14, find its area.
1256 cm²
Area A = πr² = 3.14 × 20² = 1256 cm².
11. A circle has radius 11 cm. Using π = 3.14, find its circumference.
69.08 cm
Circumference C = 2πr = 2 × 3.14 × 11 = 69.08 cm.
12. A circle has radius 8 cm. Using π = 3.14, find its circumference.
50.24 cm
Circumference C = 2πr = 2 × 3.14 × 8 = 50.24 cm.

12 questions · Seed 57 · 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 3 cm. Using π = 3.14, find its area.
3 cm · 3.14 · Circle circumference & area
2. A circle has radius 7 cm. Using π = 3.14, find its area.
7 cm · 3.14 · Circle circumference & area
3. A circle has radius 16 cm. Using π = 3.14, find its circumference.
16 cm · 3.14 · Circle circumference & area
4. A circle has radius 17 cm. Using π = 3.14, find its area.
17 cm · 3.14 · Circle circumference & area
5. A circle has radius 18 cm. Using π = 3.14, find its area.
18 cm · 3.14 · Circle circumference & area
6. A circle has radius 5 cm. Using π = 3.14, find its area.
5 cm · 3.14 · Circle circumference & area
7. A circle has radius 15 cm. Using π = 3.14, find its area.
15 cm · 3.14 · Circle circumference & area
8. A circle has radius 8 cm. Using π = 3.14, find its area.
8 cm · 3.14 · Circle circumference & area
9. A circle has radius 6 cm. Using π = 3.14, find its area.
6 cm · 3.14 · Circle circumference & area
10. A circle has radius 20 cm. Using π = 3.14, find its area.
20 cm · 3.14 · Circle circumference & area
11. A circle has radius 11 cm. Using π = 3.14, find its circumference.
11 cm · 3.14 · Circle circumference & area
12. A circle has radius 8 cm. Using π = 3.14, find its circumference.
8 cm · 3.14 · Circle circumference & area

12 questions · Seed 57 · 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 3 cm. Using π = 3.14, find its area.
28.26 cm²
Area A = πr² = 3.14 × 3² = 28.26 cm².
2. A circle has radius 7 cm. Using π = 3.14, find its area.
153.86 cm²
Area A = πr² = 3.14 × 7² = 153.86 cm².
3. A circle has radius 16 cm. Using π = 3.14, find its circumference.
100.48 cm
Circumference C = 2πr = 2 × 3.14 × 16 = 100.48 cm.
4. 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.
5. A circle has radius 18 cm. Using π = 3.14, find its area.
1017.36 cm²
Area A = πr² = 3.14 × 18² = 1017.36 cm².
6. A circle has radius 5 cm. Using π = 3.14, find its area.
78.5 cm²
Area A = πr² = 3.14 × 5² = 78.5 cm².
7. A circle has radius 15 cm. Using π = 3.14, find its area.
706.5 cm²
Area A = πr² = 3.14 × 15² = 706.5 cm².
8. A circle has radius 8 cm. Using π = 3.14, find its area.
200.96 cm²
Area A = πr² = 3.14 × 8² = 200.96 cm².
9. 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.
10. A circle has radius 20 cm. Using π = 3.14, find its area.
1256 cm²
Area A = πr² = 3.14 × 20² = 1256 cm².
11. A circle has radius 11 cm. Using π = 3.14, find its circumference.
69.08 cm
Circumference C = 2πr = 2 × 3.14 × 11 = 69.08 cm.
12. A circle has radius 8 cm. Using π = 3.14, find its circumference.
50.24 cm
Circumference C = 2πr = 2 × 3.14 × 8 = 50.24 cm.

12 questions · Seed 57 · Age guidance, not curriculum certification