The steel beam ABCD shown is simply supported at A and supported at B and D by steel cables each having a diameter of 12 mm. A force of 20 kN is applied at point C. For steel E = 209 GPa. Determine the stresses in the cables and the deflections of points B, C and D if

(a) Beam ABCD is considered to be rigid

(b) Beam ABCD has a second-area moment of I = 800,000 mm².