Several steps are required to solve this problem:

1. Consider equilibrium to determine the beam reactions at the pin and at the roller.

2. Construct the shear-force diagram for the beam to determine the shear force between x = 2 m and x = 3 m.

3. Compute the first moment of area Q for the specified points on the WT shape (i.e., H, K, and the centroid).

4. Use the transverse shear stress formula to compute the shear stresses at the specified points on the WT shape.