Question

The diameter of a circle is 18 in. Find its area in terms of π.

Answer 1

$\sf \: Diameter \: = \: 18 \: \: \: Radius \: = \: \frac{Diameter}{2} \: \: \: Radius \: = \: \frac{18}{2} \: = \: 9$

$\sf Area_{(circle)}\:=\: \pi r^2 \\ \\ \sf \: Area \: = \: \pi {9}^{2} \: \: \: \: \: \: \: \:$

$\sf Area \: = \: \pi \: 81$

Answer 2

A≈254.47in²

d Diameter

18