Question

The area of a circle is 25in^2. What is the circumference, in inches? Express your

answer in terms of pi

Answer 1

`c = 10 √(\pi)`

Explanation:

A = pi*r^2

We first plug in 25 for A

25 = pi * r^2

Solve

`r = \sqrt{ (25)/(\pi) }`

We can then plug in r for circumference formula

C = 2pi * r

`c = 2\pi \sqrt{ (25)/(\pi) }`

`c = 10 √(\pi)`

or 17.72