Chapter 11.5, Problem 5WE

To determine

To Find: The radius and area.

Answer to Problem 5WE

  $r=10units$

  $A=100\pi sq.units$

Explanation of Solution

Given: $C=20\pi$

Circumference of a circle

  $\begin{array}{l}C=2\pi r\\ 20\pi =2\pi r\\ r=\frac{20\pi }{2\pi }\\ r=10units\end{array}$

Area of circle

  $\begin{array}{l}A=\pi r^2\\ $ A=\pi {(10)}^2$A=100\pi sq.units\end{array}$