Answer
The given circle has:
circumference = $18\pi$ centimeters
area = $81\pi$ square centimeters
Work Step by Step
RECALL:
(i) The circumference (C) of a circle is given by the formula $C=2\pi{r}$ where r =radius; and
(ii) The area (A) of a circle is given by the formula $A=\pi{r^2}$ where r = radius
With a radius of 9 centimeters, use the formulas above to have:
$C=2\pi(9) = 18\pi$ centimeters
$A=\pi(9^2) = 81\pi$ square centimeters
