Regular 4-polytopeIn mathematics, a regular 4-polytope is a regular four-dimensional polytope. They are the four-dimensional analogues of the regular polyhedra in three dimensions and the regular polygons in two dimensions. There are six convex and ten star regular 4-polytopes, giving a total of sixteen. The convex regular 4-polytopes were first described by the Swiss mathematician Ludwig Schläfli in the mid-19th century. He discovered that there are precisely six such figures.
Hécatonicosachore icosaédralIn geometry, the icosahedral 120-cell, polyicosahedron, faceted 600-cell or icosaplex is a regular star 4-polytope with Schläfli symbol {3,5,5/2}. It is one of 10 regular Schläfli-Hess polytopes. It is constructed by 5 icosahedra around each edge in a pentagrammic figure. The vertex figure is a great dodecahedron. It has the same edge arrangement as the 600-cell, grand 120-cell and great 120-cell, and shares its vertices with all other Schläfli–Hess 4-polytopes except the great grand stellated 120-cell (another stellation of the 120-cell).
4-polytope uniformethumb|upright=1.5|alt=Représentation du 120-cellules rectifié selon son diagramme de Schlegel|Diagramme de Schlegel du 120-cellules rectifié. Un 4-polytope uniforme est, en géométrie, un 4-polytope isogonal dont les cellules sont des polyèdres uniformes. Il s'agit de l'équivalent de ces derniers en dimension 4.
HexacosichoreEn géométrie, l'hexacosichore ou « 600-cellules » est le 4-polytope régulier convexe qui a comme symbole de Schläfli {3, 3, 5}. Il est composé de 600 cellules tétraédriques dont 20 qui se rencontrent à chaque sommet. Ensemble, ils forment triangulaires, 720 arêtes et 120 sommets. Les arêtes forment 72 décagones réguliers plans. Chaque sommet du 600-cellules est le sommet de six de ces décagones.
