1. The problem statement, all variables and given/known data See attachment 2. Relevant equations Let u be the angle between AC and AO and v the angle between BE and BD. Ta is the tension at point A and Tb is the tension at point B. 3. The attempt at a solution Tried starting with the OAB body and got: -mg + Ta sin(u) + Tb sin(v) = 0 -Oz + Ta cos(u) + Tb cos(v) = 0 for the force equilibrium. For the moment equilibrium, I chose point A as reference. The moment due to mg is -mg*0.75, and the moment due to the vertical component of Tb should be Tb sin(v)*1.5. But doesn't the horizontal component of Tb cause a moment about point A here too? If so, what's preventing the beam OAB from rotating about point O?