Find the radius R of the star Rigel, the bright blue star in the constellation Orion, which radiates energy at a rate of 2.7×1032 W and has a surface temperature of 11,000 K. Assume that the star is spherical, and that its emissivity is 1.0. Use ? = 5.67×10?8W/m2?K4 for the Stefan-Boltzmann constant.