The document presents analytical methods for calculating stresses on an oblique section of a body subjected to direct stresses in two perpendicular directions and a shear stress. It defines equations to calculate the normal stress, shear stress, maximum shear stress, resultant stress, and direction of resultant stress on the oblique section. It also provides equations for determining the maximum and minimum principal stresses and directions of maximum shear stress and maximum principal stress. Several example problems are presented to demonstrate applying the analytical methods.