If $l_{A}$ is the moment of inertia of a mass distribution of total mass $M$ with respect to an axis $A$ through the center of gravity, sbow that its moment of inertia $l_{B}$ with respect to en exis $B$, which is parallel to $A$ and has the distance $k$ from it, is $$l_{B}=I_{A}+k^{2} M$$