The cross-section of a very long black body enclosure consists of a semicircle with its diameter D as base. The temperature of semi-circle is 1000 K and that of diameter is 500 K. Determine the shape factors for diameter-semicircle combination and the radiation heat transfer rate per unit width (in terms of D).Stephan-Boltzman constant 5.64×10–8 W/m2 -K.