area=pi times r^2
circumference=2pi times r
we are given
area=144pi ft^2
therefor
area=pi r^2
144pi=pir^2
divide both sides by pi
144=r^2
squre root both sides
12=r
subsitute
circunference=2pi r
circunference=2 times pi times 12
circumference=24pi
answer is 24pi ft
if you were to aprox pi to 3.14 and multiply you would get 75.36 ft