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Calculate the circumference and area of circles · Grade 7 · E2.3, E2.5

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Date: ______________________

1
A circle has a diameter of 18 cm. Using π ≈ 3.14, find its circumference in centimetres.
Warm-up
Answer:
2
A circle has a diameter of 6 cm. Using π ≈ 3.14, find its circumference in centimetres.
Warm-up
Answer:
3
A circle has a diameter of 20 cm. Using π ≈ 3.14, find its circumference in centimetres.
Warm-up
Answer:
4
A circle has a radius of 10 cm. Using π ≈ 3.14, find its circumference in centimetres.
On level
Answer:
5
A circle has a radius of 8 cm. Using π ≈ 3.14, find its circumference in centimetres.
On level
Answer:
6
A circle has a radius of 8 cm. Using π ≈ 3.14, find its circumference in centimetres.
On level
Answer:
7
A circle has a radius of 10 cm. Using π ≈ 3.14, find its area in square centimetres.
Challenge
Answer:
8
A circle has a radius of 5 cm. Using π ≈ 3.14, find its area in square centimetres.
Challenge
Answer:
9
A circle has a radius of 7 cm. Using π ≈ 3.14, find its area in square centimetres.
Challenge
Answer:

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Worksheet code: eyJzIjoic3BhdGlhbC1jaXJjbGUtbWVhc3VyZSIsImQiOls0MzE1NjUzNjksMjA5MTI5NzUyNSwxMzgxMjg1NzQxLDU5ODkxNzY1OCw1OTk2MjM0MCwyMDIyMzIyODY0LDE0Mzc5NzgyMDQsMTI3MjQ4Mjc2NSwyMDI3NDIzMTgwXSwidiI6MX0.c62fef62b43b

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Answer key · Calculate the circumference and area of circles

1.
56.52 — C = π × d = 3.14 × 18 = 56.52 cm.
2.
18.84 — C = π × d = 3.14 × 6 = 18.84 cm.
3.
62.8 — C = π × d = 3.14 × 20 = 62.8 cm.
4.
62.8 — C = 2 × π × r = 3.14 × 20 = 62.8 cm.
5.
50.24 — C = 2 × π × r = 3.14 × 16 = 50.24 cm.
6.
50.24 — C = 2 × π × r = 3.14 × 16 = 50.24 cm.
7.
314 — A = π × r² = 3.14 × 100 = 314 cm².
8.
78.5 — A = π × r² = 3.14 × 25 = 78.5 cm².
9.
153.86 — A = π × r² = 3.14 × 49 = 153.86 cm².