Arectangular sign over a store has a weight of 150 lb, with the center of gravity in the center of the rectangle. the support against the wall at point c may be treated as a ball-and-socket joint. at corner d support is provided in the y-direction only. calculate the tensions t1 and t2 in the supporting wires, the total force supported at c, and the lateral force r supported at d. the force r is positive if it points in the +y-direction, and negative if it points in the -y-direction.