The problem of deciding whether two objects are similar or not is very important in the classification of shapes of objects for robot vision and in the creation of knowledge based systems. This paper describes a method for determining the similarities of two convex polyhedra with unequal number of vertices. The method presented for deciding the similarities of objects with equal number of vertices is extended with the following concepts : (1) In order to calculate the degree of similarity, a method for equalizing the number of vertices between two objects is introduced. (2) The additional factor affecting the similarity, which represents the difference in the number of vertices between two objects, is considered. The results of similarity tests on some kinds of objects show that the method is good for deciding similarities.
