In the structure shown, an 8-mm-diameter pin is used at A, and 12-mm-diameter pins are used at B and D. Knowing that the ultimate shearing stress is 100 MPa at all connections and that the ultimate normal stress is 250 MPa in each of the two links joiningẞ and D, determine the allowable load P if an overall factor of safety of 2.8 is desired. 8 mm P = kN Top view 180 mm 140 mm 12 mm 20 mm B B C По в P 8 mm 8 mm D D 12 mm Front view Side view