| Regular decagram | |
|---|---|
&sq=&lang=&file=File:Regular_star_polygon_10-3.svg) A regular decagram | |
| Type | Regular star polygon |
| Edges and vertices | 10 |
| Schläfli symbol | {10/3} t{5/3} |
| Coxeter–Dynkin diagrams |       |
| Symmetry group | Dihedral (D10) |
| Internal angle (degrees) | 72° |
| Properties | star, cyclic, equilateral, isogonal, isotoxal |
| Dual polygon | self |
| Star polygons |
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&sq=&lang=&file=File:Sultan_Barquq%27s_Qur%27an_decagram.jpg)
In geometry, a decagram is a 10-point star polygon. There is one regular decagram, containing the vertices of a regular decagon, but connected by every third point. Its Schläfli symbol is {10/3}.[1]
The name decagram combines a numeral prefix, deca-, with the Greek suffix -gram. The -gram suffix derives from γραμμῆς (grammēs) meaning a line.[2]
- ^ Barnes, John (2012), Gems of Geometry, Springer, pp. 28–29, ISBN 9783642309649.
- ^ γραμμή, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus