[SOLVED] Moment of Inertia Problem: Perpendicular Axes THM 1. The problem statement, all variables and given/known data First, the problem asked us to basically prove the Perp. Axes Thm and then use it to prove that the MoI of a thin, uniform square sheet with mass M and side L through ANY axis in its plane is equal to 1/2 M L^2 2. Relevant equations The moment of inertia for a square sheet of a perpendicular axis through its center of mass is 1/6 M L^2 3. The attempt at a solution First, I tried to simply say that I_x is perp. to I_y and that their sum is I_o which is equal to 1/6 M L^2 (above). And since the square is uniform, I_x = I_y = 1/2 I_o but this gave me I_x = 1/12 M L^2. Is it possible that the book has a misprint? How is it possible for the moments of inertia of an axis in the plane to be 3 times the MoI through the center of mass?