120 mm 3kN 120 mm D K но 19 kN

The steel pipe AB has a 72-mm outer diameter and a 5-mm wall thickness. Knowing that the arm CDE is rigidly attached to the pipe, compute the length of the pipe, L, that causes the von Mises equivalent stress to be same at points H and K

This IS NOT a graded assignment, it is supplementary study material.