since r = h, we can substitute that into the equation
V = pi * r^2 * r = pi * r^3
Since we know the volume, we can put that in too.
64 pi = pi * r^3 now let's divide both sides by pi.
64 pi/pi = pi * r^3/pi
64 = r^3
cuberoot(64) = r
cuberoot (2^6 )=r
4 = r
