Introduction
The area moment of inertia (also referred to as second moment of area) is a geometrical property of a shape describing the distribution of points around an axis. In classical mechanics it is used as a measure of a body’s resistance against bending.
Note that next to the area moment of inertia, the polar moment of inertia is used as a measure of a body’s resistance to torsion (see Beam theory: Torsion sheet). Also, the area moment of inertia should not be confused with the mass moment of inertia, which is used as a measure of how an object resists rotational acceleration about a particular axis (see Mass moment of inertia sheet). The area moment of inertia is typically denoted with an I and has an axis that lies in the plane, the polar second moment of inertia is typically denoted with a J and has an axis perpendicular to the plane.
Crosssection  Area moment of inertia 

$$I_x=I_y=\frac{\pi}{4}r^4$$  
$$I_x=I_y=\frac{\pi}{4}\left(r_o^4r_i^4\right)$$  
$$I_x=\frac{{wh}^3}{12}$$ $$I_y=\frac{w^3h}{12}$$ 

$$I_x=\frac{w_oh_o^3w_ih_i^3}{12}$$ $$I_y=\frac{w_o^3h_ow_i^3h_i}{12}$$ 

$$I_x=\frac{wh^3}{12}\frac{\left(wt_2\right)\left(h2t_1\right)^3}{12}$$ $$I_y=\frac{t_2^3\left(h2t_1\right)}{12}+\frac{2w^3t_1}{12}$$ 

$$I_x=\ \frac{wh^3}{36}$$ $$I_y=\frac{w^3h}{48}$$ 

$$I_x=\frac{\pi}{4}{r_1r}_2^3$$ $$I_y=\frac{\pi}{4}r_1^3r_2$$ 