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|- |bgcolor=#e7dcc3|Coxeter-Dynkin diagrams|| |- |bgcolor=#e7dcc3|8-faces||512 |- |bgcolor=#e7dcc3|7-faces||2304 |- |bgcolor=#e7dcc3|6-faces||4608 |- |bgcolor=#e7dcc3|5-faces||5376 |- |bgcolor=#e7dcc3|4-faces||4032 |- |bgcolor=#e7dcc3|Cells||2016 |- |bgcolor=#e7dcc3|Faces||672 |- |bgcolor=#e7dcc3|Edges||144 |- |bgcolor=#e7dcc3|Vertices||18 |- |bgcolor=#e7dcc3|Vertex figure||Octacross |- |bgcolor=#e7dcc3|Petrie polygon||Octadecagon |- |bgcolor=#e7dcc3|Coxeter groups||C9, () D9, () |- |bgcolor=#e7dcc3|Dual||9-cube |- |bgcolor=#e7dcc3|Properties||convex |} In geometry, a 9-orthoplex or 9-cross polytope, is a regular 9-polytope with 18 vertices, 144 edges, 672 triangle faces, 2016 tetrahedron cells, 4032 5-cells ''4-faces'', 5376 5-simplex ''5-faces'', 4608 6-simplex ''6-faces'', 2304 7-simplex ''7-faces'', and 512 8-simplex ''8-faces''. It has two constructed forms, the first being regular with Schläfli symbol , and the second with alternately labeled (checkerboarded) facets, with Schläfli symbol or Coxeter symbol 611. It is one of an infinite family of polytopes, called cross-polytopes or ''orthoplexes''. The dual polytope is the 9-hypercube or enneract. == Alternate names== * Enneacross, derived from combining the family name ''cross polytope'' with ''ennea'' for nine (dimensions) in Greek * Pentacosidodecayotton as a 512-facetted 9-polytope (polyyotton) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「9-orthoplex」の詳細全文を読む スポンサード リンク
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