The diagram for this quesion is at http://www.drewtemp.com/helios/physics.gif The first thing that i did was that i made the free body diagram. From my knowledge i would say that AB and BC are in compression and AC is in tension (i think that is correct). Now the question asked to take moments at B for finding the force in AC whether it be tension or compression, however when i do that it seems like the forces just cancel off each other, and that is where i am stuck Here is the link for my free body diagram: http://www.drewtemp.com/helios/physics_freebody.gif 1. What i want to find is which members are in tension and compression (AB, BC, AC)? 2. What is the force at AC? The weight of AC is negligible. 3. What force from the left (the wind) is required to make the truss pivot at C?