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

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Worksheet code: eyJzIjoic3BhdGlhbC1jaXJjbGUtbWVhc3VyZSIsImQiOls5MTQ3MDg3NDcsMTc5MzIzODMyMiwxNDAyNjcyOTI3LDY2NjA4OTI3Nyw5NzU5NjIwMTEsMTA1OTA2MTA2MCw3NDEzNTYxMTMsMzEwOTc5MzMxLDE4MzgxNzc5NTddLCJ2IjoxfQ.649729626e80

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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.
37.68 — C = π × d = 3.14 × 12 = 37.68 cm.
3.
25.12 — C = π × d = 3.14 × 8 = 25.12 cm.
4.
25.12 — C = 2 × π × r = 3.14 × 8 = 25.12 cm.
5.
18.84 — C = 2 × π × r = 3.14 × 6 = 18.84 cm.
6.
12.56 — C = 2 × π × r = 3.14 × 4 = 12.56 cm.
7.
314 — A = π × r² = 3.14 × 100 = 314 cm².
8.
50.24 — A = π × r² = 3.14 × 16 = 50.24 cm².
9.
254.34 — A = π × r² = 3.14 × 81 = 254.34 cm².