I came across this example on the net : We are integrating over the region that is the area inside of r = 3 + 2 sin θ and outside of r = 2, working in polar coordinates (r,θ). What is the limits of integration for θ? # I already know the answer. But I have no idea how to arrive at the solution. # Do I sketch r = 3 + 2 sin θ and r = 2? r = 2 is just circle centered at origin with radius 2. What about r = 3 + 2 sin θ?