Question

determine (a) the area and (b) the circumference of the circle.
a. the area of the circle is
(type an integer or decimal rounded to the nearest hundredth as needed.)

Explanation:

Step1: Recall area formula

The formula for the area of a circle is $A = \pi r^{2}$, where $r$ is the radius. Given $r = 9$ cm.
$A=\pi\times9^{2}$

Step2: Calculate the area

$A = 81\pi\approx81\times3.14159 = 254.46979\approx254.47$ $cm^{2}$

Step3: Recall circumference formula

The formula for the circumference of a circle is $C = 2\pi r$.
$C = 2\times\pi\times9$

Step4: Calculate the circumference

$C=18\pi\approx18\times3.14159 = 56.54862\approx56.55$ cm

Answer:

a. $254.47$ $cm^{2}$
b. $56.55$ cm