The radiation configuration factor, F_1-2, is defined as the total fraction of diffuse radiant energy leaving surface 1 that is directly incident upon surface 2.

Generally lacking in the literature are configuration factors for geometries involving triangular areas. This paper includes numerical values for nine such geometries and simple algebraic equations for an additional thirteen. The general configuration is given as Fig. 1 with the triangular areas contained in perpendicular rectangulars with a common edge. The nuinerical results were obtained by direct integration, accompanied in most cases by a numerical solution involving Simpson's rule