i) Moment of Inertia: Moment of Inertia of a body about any axis is equal to the product of the area of the body and square of the distance of its centroid from that axis.

ii) Radius of Gyration: Radius of Gyration of a given area about any axis is that distance from the given axis at which the entire area is assumed to be concentrated without changing the M. I. about the given axis.