Jack knows the surface area of a cylinder and its radius. he wants to find the cylinder's height. he needs to rewrite the formula a=2pi r(r+h) to find the cylinder's height (h) in terms of the cylinder’s surface area (a) and its radius (r). which is the correct formula?
a h=r+a/2pir
b h=a/2pir
c a/2pir -r^2
d a/2pir -r