State and prove perpendicular axis theorem.

Explanation

Perpendicular axis theorem: This perpendicular axis theorem holds good only for plane laminar objects.
The theorem states that the moment of inertia of a plane laminar body about an axis perpendicular to its plane is equal to the sum of moments of inertia about two perpendicular axes lying in the plane of the body such that all the three axes are mutually perpendicular and have a common point.