#### Answer

6.32

#### Work Step by Step

Use the formula for the area of a circle.
$A=\pi r^2$
substitute
$10\pi=\pi r^2$
divide each side by $\pi$
$10\pi\div\pi=\pi r^2\div\pi$
$10=r^2$
take the square root of each side
$\sqrt{10}=\sqrt{r^2}$
$3.16=r$
The diameter is twice the radius.
$d=2r=2(3.16)=6.32$