Magnetic Graph Co-ordinate Board with marker To teach congruency of triangle, classification by their angle and sides. Ideal for use in school Mathematics Laboratory to help primary and secondary students learn basic principles and concepts. Developing Geometric thinking · Congruence & Similarity · Angle sum Properties · Discovering properties & clarification of triangles · Seeing relationship between different shapes Total 5 set of different types of triangles in different colour pen (ACRYLIC).