For my job I have to calculate the maximum shear stress in a triangular thin wall steel beam. I know how to calculate this for a retangular shape. The general formula is: tau=Vy*Sza/(b*Iz) with: tau= shear stress Vy=force Sza = statistical moment b= width Iz = moment of Inertia I just don't see how I could calculate the statistical moment for the triangle. It is a closed profile, therefore there is no point where the shear stress is zero and in contrary to the retangular shape the 'legs' don't have equal direction so it can not just be divided by two. I hope somebody can help me. Thank you!