1. The problem statement, all variables and given/known data two masses, m1 and m2, are hung from a point, P, by two string, L1 and L2, the masses are connected by a rod, length D, of negligible mass. The angle between the strings is theta, the angle between L2 and horizontal line through P is Phi. so essentially it looks like a hanger with a mass at both ends of it. 2. Relevant equations The formula for the Lagrangian is simply L=T-U, where T and U are the Potential and Kinetic energy. To find the energy I'm going to need velocity's which I think I can get by taking the Derivative of the position equations. 3. The attempt at a solution I am going to use phi as my generalized coordinate, and if this were a simple pendulum I think this problem would be pretty easy, you take the derivative of your position equations to get velocity then use T=1/2MV^2 and U=mgh and then plug and chug. With this problem having two masses separated by a rigid rod I'm completely stumped on how to go about this. Any help at all is greatly appreciated.