If the area of a circle is 144pi square feet, find its circumference.
Select the correct option.
A) 65 pi feet	B) 24 pi feet	C) 42 pi feet	D) 18 pi feet	E) 64 pi feet
The area is given by pi * r * r. Hence   pi * r *r = 144 pi   r *r = 81 ; hence r = 12 feet   The circumference is given by   2 *pi *r = 2 * pi * 12 = 24 pi feet   correct answer 24 pi feet
<result>B</result>
If the area of a circle is 144pi square feet, find its circumference.