A square is made by joining four rods each of mass M and length L. Its moment of inertia about an axis PQ, in its plane and passing through one of its corner is

Axis is parallel to the diagonal of the square. The moment of inertia of the square frame about the center perpendicular to the plane is 4ML212+ML24=4ML23 then about the diagonal 2ML23then moment of inertia about the given axis is 2ML23+4ML22= 8ML23