Chapter 11.5, Problem 8CE

To determine

To Find: The radius and circumference.

Answer to Problem 8CE

  $r=12units$

  $C=24\pi units$

Explanation of Solution

Given: $A=144\pi$

Area of circle

  $\begin{array}{l}A=\pi r^2\\ $ 144\pi =\pi {(r)}^2$r^2=\frac{144\pi }{\pi }\\ r^2=144\\ r=12units\end{array}$

Circumference of a circle

  $\begin{array}{l}C=2\pi r\\ C=2\pi (12)\\ C=24\pi units\end{array}$