proof forces parallel to members in simple truss

The video tutorial provides a formal proof that internal forces in simple trusses must be parallel to the members, based on three key assumptions: pin joints, no friction, and negligible mass. It explains the use of free body diagrams and equilibrium conditions to demonstrate that forces are purely axial. The tutorial also covers the importance of questioning assumptions and provides a step-by-step proof of axial forces in trusses.

What new insight or understanding did you gain from this video?