The figure shows three forces acting on a pin-supported rectangular plate at points A, B, and C. Use the scalar method of computing moments in this problem. a. Compute the moment of the force at A about D and write your answer in vector form (note: you can use the scalar method to find the moment). b. Compute the magnitude and orientation (0 < 0 < 180) of the smallest force FB that creates the same moment about D that you found in part (a). c. If FB = 20 lb and 0 = 30, compute the magnitude of the horizontal force Fc that makes the resultant moment of these three forces about D equal to zero. -16 in 24 in 30 in 23 55 lb A D 20 in Fc C B FB