For a population of deformed objects in which the initial angular relationship between two lines can be known or the angular shear strain can be measured, Wellman devised this method. With reference to a line such as AB, the length of hinge lines of all fossils are plotted with reference to the angle betwen AB and each hinge line. The procedure is repeated for all medribs. The resulting plot gives the mean ratio of axes of finite strain in the deformed surface considered. This is useful if the strain varied to the degree that analysing just two may give slightly differening results.