A pentagramMathworldPlanetmath is the figure formed by the five diagonals of a regularPlanetmathPlanetmathPlanetmath ( pentagonMathworldPlanetmath.  The name comes from the Greek πενταγϱαμμoν. Its are πεντε ‘five’ and γϱαμμoς ‘stoke, ’.  These Greek are transliterated as pentagrammon, pente, and grammos, respectively.

In the picture below, a regular pentagon is drawn dashed in black, the pentagram is drawn in blue, and the regular pentagon in the middle of the pentagram is shaded in cyan.

All pentagrams are similarMathworldPlanetmath.  If the length of the pentagon diagonal is d, then each side of the small pentagon in the middle of the pentagram is of length  (5-2)d.

Title pentagram
Canonical name Pentagram
Date of creation 2013-03-22 17:08:52
Last modified on 2013-03-22 17:08:52
Owner pahio (2872)
Last modified by pahio (2872)
Numerical id 11
Author pahio (2872)
Entry type Definition
Classification msc 51F99