A right circular cone has a volume of $12\pi$ cubic centimeters. The height of the cone is 4 cm. How many centimeters is the circumference of the base of the cone, in terms of $\pi$?
volume of a cone is 1/3*pi*r^2* h
12pi = 1/3*pi*r^2*4
circumfrence is pi*2r
circumfrence = 6pi