Find masses on an equilibrium plane

[Naldo6]

Can anyone help me on how to calculate mass C, mass D, and mass A from the diagram in the atachment whose is in equilibrium if:

The object B has mass of 0.785 kg. Determine the mass of object C. Assume L1 = 30.4 cm, L2 = 7.50 cm, L3 = 14.6 cm, L4 = 5.00 cm, L5 = 16.8 cm and L6 = 5.00 cm. (Neglect the weights of the crossbars.)

 

[heth]

Same as your previous questions - show some work and an attempt at a solution, as per the forum rules.