The second moment of an area of an object about any axis can be estimated by concentrating its area into a thin strip parallel to the same axis. The distance between this strip and the axis is defined as the radius of gyration. It is expressed as the square root of the ratio of the second moment of area about that axis and the area. Similarly, the polar radius of gyration is expressed as the square root of the ratio between the polar moment and area. Consider a rectangular beam with a cross-sectional area equal to the product of its height and width. The second moment of area about a centroidal axis is obtained by multiplying the rectangle's width by the cube of its height and dividing it by twelve. The radius of gyration is calculated using the area and second moment of area. The result equals the beam's height divided by the square root of twelve. A higher radius of gyration indicates greater resistance against bending deformation due to an increased moment of inertia.