1. The problem statement, all variables and given/known data i know that to calculate the shear stress, formula is τ= (V)(Q)/ (I)(t) So, why the author choose to use Ixx, but not Iyy for shear stress at P? 2. Relevant equations 3. The attempt at a solution IMO, we should done the question in 2 ways, which are by using Ixx and Iyy respectively...Am i right?