A uniform rectangular plate of width d, height h, and weight W is supported with its top

Question:

A uniform rectangular plate of width d, height h, and weight W is supported with its top and bottom edges horizontal (Fig. 11.48). At the lower left comer there is a hinge and at the upper right corner there is a cable.
(a) For what angle 6 with the vertical will the tension in the cable be the least, and what is that tension?
(b) Under the conditions of part (a), find the horizontal and vertical components of the force that the hinge exerts on the plate.