Abstract: Complementary geometric construction modules, each derived from a rectangular prism, with end faces formed obliquely to each other and to the longitudinal axis of the prism, with the two oblique faces touching each other at a point on the longitudinal edge of the prism, each module forming a hexahedron, each being the reverse or mirror-shape of the other, and providing bilateral symmetry when the two corresponding faces on the modules, are in full contact with each other; the modules in multiple sets adapted to be formed into a wide variety of sculptured architectural shapes, unique in appearance.