The weight of the plate acts at the center of gravity, ie with homogeneous weight distribution in the middle of the plate.
If you choose the tip of the right support as the reference point and count torques in the counterclockwise direction as positive (M-vector protrudes from the plane of the drawing), the torque due to the weight of the plate would be
The weight of the plate acts at the center of gravity, ie with homogeneous weight distribution in the middle of the plate.
If you choose the tip of the right support as the reference point and count torques in the counterclockwise direction as positive (M-vector protrudes from the plane of the drawing), the torque due to the weight of the plate would be