1. The problem statement, all variables and given/known data Hello, in the attached file shows a picture of the problem I need to resolve. The question asks to calculate the internal force in the member BC. There is a pin support located at joint A and D, which is not shown in my diagram, and it is also symmetrical, which makes things slightly easier. 2. Relevant equations See attached file. 3. The attempt at a solution I calculated the forces in the y direction using the equilibrium equation, and then calculated the angle between member AE and AB using basic trigonometry to be 26.57 degrees. I then resolved the internal forces in members AE and AB. However, I am unable to determine what else I can do with resolving further internal forces in this structure. For all other joints, there are at least 2 unknown forces, for which I am unable to determine any other internal forces. What should be my next approach? Thanks, forum.