1. The problem statement, all variables and given/known data In the attachment 2. Relevant equations 3. The attempt at a solution I have been solving this question for quite some time but I cant get the answer yet. I offset all the forces to point C and I get the following values: Moment at y-axis, M(y) = 10Nm Moment at z-axis, M(z) = 48Nm Stress at x-axis = -M(z) x (21mm) / I = -20MPa Stress at z-axis = 0 Shear stress at xz plane = Tc/J = (40Nm) (21mm) / J = 8.33MPa By applying the following equations to get the principle strain, tan(2theta)=2(Shear stress at xz plane) /(Stress at x-axis - Stress at z-axis) I cant get the correct answer. Can anyone help me? Thanks in advance.