1. The problem statement, all variables and given/known data Hi I am looking at a unit sphere. Two squares are projected onto the sphere on opposite ends, as shown in figure 1 (the figure only shows one square, the other one is at the opposite end). There are two more sets of these squares, each set in its own dimension, so there are a total of six squares projected onto the sphere opposite to eachother pairwise. The side of each square is 0.25 long. What I want to find is the total solid angle which is not covered by the squares. Can I get a hint to what the easiest way to do this is? I guess I need to do the integral over θ and phi, but it isn't trivial to me what the boundaries are. Best, Niles.