Find the points of intersection (r,theta) of the curves. Points intersect at the pole and one other point.

r=2(1-cos(theta))

r=4sin(theta)

How do you find theta? I know the one of the points is zero but i'm looking for the other point of intersection. I also know what r and theta is if i graph these equations but how do you work it out without a calculator? Details would be appreciated.