Question

The circumference of the circle exceeds the diameter by 16.8cm .find the radius of the circle.

Answer 1

We know that circumference of a circle = 2pir.
We know that diameter = 2r.
Given circumference of a circle exceeds diameter by 16.8cm.
2pir - 2r = 16.8
2r(pi - 1) = 16.8
2r(22/7 - 1) = 16.8
2r(22 - 7/7) = 16.8
2r(15/7) = 16.8
30r = 16.8 * 7
30r = 117.6
r = 117.6/30
r = 3.92 cm.
Therefore the radius of the circle = 3.92cm.