Enneagrams shown as sequential stellations
Edges and vertices9
Symmetry groupDihedral (D9)
Internal angle (degrees)100° {9/2}
20° {9/4}

In geometry, an enneagram (🟙 U+1F7D9) is a nine-pointed plane figure. It is sometimes called a nonagram, nonangle, or enneagon.[1]

The word 'enneagram' combines the numeral prefix ennea- with the Greek suffix -gram. The gram suffix derives from γραμμῆ (grammē) meaning a line.[2]

Regular enneagram

A regular enneagram is a 9-sided star polygon. It is constructed using the same points as the regular enneagon, but the points are connected in fixed steps. Two forms of regular enneagram exist:

There is also a star figure, {9/3} or 3{3}, made from the regular enneagon points but connected as a compound of three equilateral triangles.[3][4] (If the triangles are alternately interlaced, this results in a Brunnian link.) This star figure is sometimes known as the star of Goliath, after {6/2} or 2{3}, the star of David.[5]

Compound Regular star Regular
Regular star

Complete graph K9


{9/3} or 3{3}


Other enneagram figures

The final stellation of the icosahedron has 2-isogonal enneagram faces. It is a 9/4 wound star polyhedron, but the vertices are not equally spaced.

The Fourth Way teachings and the Enneagram of Personality use an irregular enneagram consisting of an equilateral triangle and an irregular hexagram based on 142857.

The Bahá'í nine-pointed star

A 9/3 enneagram

The nine-pointed star or enneagram can also symbolize the nine gifts or fruits of the Holy Spirit.[6]

In popular culture

See also


  1. ^ "Between a square rock and a hard pentagon: Fractional polygons". 28 September 2017.
  2. ^ γραμμή, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus.
  3. ^ Grünbaum, B. and G. C. Shephard; Tilings and patterns, New York: W. H. Freeman & Co., (1987), ISBN 0-7167-1193-1.
  4. ^ Grünbaum, B.; Polyhedra with Hollow Faces, Proc of NATO-ASI Conference on Polytopes ... etc. (Toronto 1993), ed T. Bisztriczky et al., Kluwer Academic (1994) pp. 43-70.
  5. ^ Weisstein, Eric W. "Nonagram". mathworld.wolfram.com.
  6. ^ Our Christian Symbols by Friedrich Rest (1954), ISBN 0-8298-0099-9, page 13.
  7. ^ "slipknot". eBay.