Area of a circle
Use area = pi * radius^2 (pi approx. 3.14) to find the area of a circle from its radius or diameter. Unlimited questions, five difficulty levels, and a full worked solution every time — free.
Try one
A circular pool has a radius of 5 m. Using pi = 3.14, what is its area?
Answer: 78.5
See one solved, step by step
A manhole cover has a diameter of 16 cm. Using pi = 3.14, what is its area?
📘 Worked solution
1radius = diameter / 2 = 16 / 2 = 8Area needs the radius, and the radius is half the diameter.
2A = π · r2 = 3.14 · 82 = 3.14 · 64Square the radius, then multiply by pi (3.14).
3= 200.96 cm2Multiply it out.
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