# How do you find the circumference and area of a circle with diameter of 9 inches?

Oct 12, 2015

Diameter = 9 inches
Radius = r = diameter /2 = 4.5 inches

For Circumference:

$C = 2. \pi . r$
$C = 2 . 3.142 . 4.5$
$C = 28.278$ inches

For Area:

$A = \pi . {r}^{2}$
$A = 3.142 . {\left(4.5\right)}^{2}$
$A = 63.62$ Sq.Inches