1. The problem statement, all variables and given/known data Hello. I have some troubles with a truss problem. In fact i believe i have correctly identified the direction of the forces involved in the rods, but i cannot identify which rod is in compression or which is in tension. Are there any tips/rules to identify only with a force diagram? https://www.physicsforums.com/attachment.php?attachmentid=9821&d=1177005673 3. The attempt at a solution Well i have resolved forces at each joint and put a direction (of the force) in the rod so that the net force at any joint is zero (Since the system is in equilibrium). 1. Direction of force at P : Horizontally to the left. 2. Direction of force at R : Vertically upwards. 3. Direction of force at Q : Vertically downwards. 4. Direction of force at S : Horizontally to the left. However i cannot figure the least which rods are in compression or in tension.