A circular pen has an area of 64pi square yards. What is the circumference of the pen?

1 Answer
Jan 23, 2018

16pi

Explanation:

To find the circumference of a circle, you need the radius.

Remember that the area of a circle is A=pir^2

Since we know the area, we can plug it in for A

64pi=pir^2
64cancelpi=cancelpir^2
64=r^2

Take the square root of both sides to find the radius:

r=8

Now, use the circumference formula of 2pir

C=2pi(8)

This simplifies to the circumference equalling 16pi