Catalan solid explained

The Catalan solids are the dual polyhedron of Archimedean solids, a set of thirteen polyhedrons with highly symmetric forms semiregular polyhedrons in which two or more polygonal of their faces are met at a vertex. A polyhedron can have a dual by corresponding vertices to the faces of the other polyhedron, and the edges between pairs of vertices of one correspond to the edges between pairs of faces of the other. One way to construct the Catalan solids is by using the method of Dorman Luke construction.

These solids are face-transitive or isohedral because their faces are transitive to one another, but they are not vertex-transitive because their vertices are not transitive to one another. Their dual, the Archimedean solids, are vertex-transitive but not face-transitive. Each has constant dihedral angles, meaning the angle between any two adjacent faces is the same. Additionally, both Catalan solids rhombic dodecahedron and rhombic triacontahedron are edge-transitive, meaning there is an isometry between any two edges preserving the symmetry of the whole. These solids were also already discovered by Johannes Kepler during the study of zonohedrons, until Eugene Catalan first completed the list of the thirteen solids in 1865.

The pentagonal icositetrahedron and the pentagonal hexecontahedron are chiral because they are dual to the snub cube and snub dodecahedron respectively, which are chiral; that is, these two solids are not their own mirror images.

Eleven of the thirteen Catalan solids are known to have the Rupert property (a copy of the same solid can be passed through a hole in the solid).

The thirteen Catalan solids! Name! Image! Faces! Edges! Vertices! Dihedral angle! Point group
triakis tetrahedron12 isosceles triangles188129.521°Td
rhombic dodecahedron12 rhombi2414120°Oh
triakis octahedron24 isosceles triangles3614147.350°Oh
tetrakis hexahedron24 isosceles triangles3614143.130°Oh
deltoidal icositetrahedron24 kites4826138.118°Oh
disdyakis dodecahedron48 scalene triangles7226155.082°Oh
pentagonal icositetrahedron24 pentagons6038136.309°O
rhombic triacontahedron30 rhombi6032144°Ih
triakis icosahedron60 isosceles triangles9032160.613°Ih
pentakis dodecahedron60 isosceles triangles9032156.719°Ih
deltoidal hexecontahedron60 kites12062154.121°Ih
disdyakis triacontahedron120 scalene triangles18062164.888°Ih
pentagonal hexecontahedron60 pentagons15092153.179°I

References

Works cited

External links