Determine the beam cross-sectional areas that result in the minimum weight for the truss we studied in Sec. 12.2 (Figure). The critical buckling and maximum tensile strengths of compression and tension members are 10 and 20 ksi, respectively. The truss is to be constructed of steel (density = 3.5 lb/ft-in2). Note that the length of the horizontal member (2) is 50 ft. Also, recall that the stress in each member is equal to the force divided by cross-sectional area. Set up the problem as a linear programming problem. Obtain the solution graphically and with the Excel solver.