Four masses are arrnaged as shown below. They are connected by rigid, massless rods of lengths 0.75 m and 0.50 m. What torque must be applied to cause an angular acceleration of 0.75 rad/s^2?

A--------B

l

l

------------(Axis of rotation)

l

l

D--------C

(B and C are connected by a rod, I couldn't get the picture to look right)

A= 4 kg, B=3 kg, C=5 kg, D=2 kg

I know that torque=I(rotational inertia) times angular acceleration, but I don't know what equation for I to use. None of the equations given in the book for I, (hoop, cylinder, sphere, rod, and plate) seem to fit. I'm stuck!

I would appreciate any help!