Every polygon falls into four semi-interchangeable categories. Closed shapes with more than three sides and angles can either be convex, concave, regular or irregular polygons. A regular (or ...

A polygon is regular if it is uniform and its faces are all alike. The regular convex polyhedra are the five Platonic solids, which have been known since classical Greece. The ancient Greek ...

A French mathematician has completed the classification of all convex pentagons, and therefore all convex polygons, that tile the plane. One of the oldest problems in geometry asks which shapes tile ...