http://[ATTACH=full]199940[/ATTACH] I am having trouble with this truss problem. I have attached my work so far. I used the entire structure as a system first and did the sum of the forces equals zero but I don't know how I can finish the moment at a because I dont know the x and y distances for the 500N force. and I have no idea where to go from there and have been working on it for a long time. I get so lost with the angles in problems like these. help would be appreciated. thanks!