1. The problem statement, all variables and given/known data ignore all the other writing! 3. The attempt at a solution I can't tell where I'm making a mistake. Probably a massive oversight somewhere but I don't know where! First find the reaction forces at the pin and roller by treating everything as a rigid body. (I am now aware this isn't necessary since I can start at joint D since one of the equations has 1 unknown, but this method is still bugging me) sum F_x = 0 R_Dx + R_Ax - 5000sin(15) = 0 (equation 1) sum F_y = 0 -R_Ay - 5000cos(15) = 0 so R_Ay = -4829 N sum Moments about point A = 0 (2*R_Dx) - (5*5000sin(15)) = 0 so R_Dx = 3235 N so plugging R_Dx into equation 1 gives R_Ax = -1941 N starting at joint D sum F_x = 0 R_Dx + BD = 0 so BD = -R_Dx = -3235 N but the answer says it is 12.89 kN compression! I can't continue because everything else will be wrong. What am I screwing up on?