Catalan solids are a concept from geometry: For each Archimedean solid there is a Catalan solid that is its dual polyhedron. In total, there are thirteen Catalan solids (as there are thirteen Archimedean solids). They are named after the Belgian mathematician Eugène Charles Catalan of the 19th centurty. Each Catalan solid is a convex polyhedron. Like with Archimedean solids, each surface is made of the same shape.