Find the concrete cross section and the steel area required for a simply supported rectangular beam with a span of 7.2 m that is to carry a computed factored load moment, Mu- 350 kN-m = fc' = 28 MPa and fy = 420 MPa bd ?? Using reinforcement ratio of p=0.005 OM, Mu M = ops,b|1 - 0.59 OMn = Rbd Pfy f p=0.90