Calculate the second moment of area (also known as moment of inertia of plane area, area moment of inertia, or second area moment) and the section modulus of a profile with circular cross section and diameter *A*. Use this to calculate deflection or stress in a loaded profile.

\( I_{yy} = \dfrac {πA^{4}}{64} \)

\( W_{yy} = \dfrac {πA^{3}}{32} \)