Question

A circular pool is enclosed by a square fence so that the pool touches the fence in four places, as shown in the figure below. If the circumference of the pool is 100π feet, how much fencing was used to enclose the area?

Answer 1

c=pid
100pi=pid
divide both sides by pi
100=d

100=legnth of 1 side of the fence

4*100=400
anwer is 400ft

Answer 2

Circumference = 2πr
Circumference = 100π
100π / π = 100
100 / 2 = 50
50 = r (radius)
2r = d (diameter)
50 x 2 = d
d = 100
100 + 100 + 100 + 100 = 400 (sides of the square)