The original magformers magnetic construction set and a favourite seller the world over contains squares and triangles and the set to use to build the famous magformers rhombicuboctahedron includes step by step idea booklet showing numerous models to build teaches shape transformation from 2d to 3d construction children can use basic magformers geometric shapes to create 2d flat plans known as nets but also 3d figures very easy to lay magformers flat forming a mathematical net and pull them up