This paper deals with the extension of the method, which was proposed by TOMIZAWA in part (1) and (2) of the same titled previous paper, for analyzing a cubic rectangular rigid frame in consideration of axial distortion of columns. The characteristic of this method i.e., to be able to calcurate the stresses of multistoried rigid frame by this method in less executing time than by the stiffness matrix method, is kept completely in this extension.
