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Regular heptagram (7/2)
A regular heptagram
TypeRegular star polygon
Edges and vertices7
Schläfli symbol{7/2}
Coxeter–Dynkin diagrams
Symmetry groupDihedral (D7)
Internal angle (degrees)≈77.143°
Propertiesstar, cyclic, equilateral, isogonal, isotoxal
Dual polygonself
Regular heptagram (7/3)
A regular heptagram
TypeRegular star polygon
Edges and vertices7
Schläfli symbol{7/3}
Coxeter–Dynkin diagrams
Symmetry groupDihedral (D7)
Internal angle (degrees)≈25.714°
Propertiesstar, cyclic, equilateral, isogonal, isotoxal
Dual polygonself

A heptagram, septagram, septegram or septogram is a seven-point star drawn with seven straight strokes.

The name heptagram combines a numeral prefix, hepta-, with the Greek suffix -gram. The -gram suffix derives from γραμμῆ (grammē) meaning a line.[1]

Geometry

In general, a heptagram is any self-intersecting heptagon (7-sided polygon).

There are two regular heptagrams, labeled as {7/2} and {7/3}, with the second number representing the vertex interval step from a regular heptagon, {7/1}.

This is the smallest star polygon that can be drawn in two forms, as irreducible fractions. The two heptagrams are sometimes called the heptagram (for {7/2}) and the great heptagram (for {7/3}).

The previous one, the regular hexagram {6/2}, is a compound of two triangles. The smallest star polygon is the {5/2} pentagram.

The next one is the {8/3} octagram and its related {8/2} star figure (a compound of two squares), followed by the regular enneagram, which also has two forms: {9/2} and {9/4}, as well as one compound of three triangles {9/3}.


{7/2}

{7/3}

{7}+{7/2}+{7/3}

7-2 prism

7-3 prism

Complete graph

7-2 antiprism

7-3 antiprism

7-4 antiprism

Uses

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Flags and heraldry

Law enforcement

Religious and occult symbolism

Seal of Babalon and the A∴A∴

In popular culture

Logo of Maersk

Variants

See also

References

  1. ^ γραμμή, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
  2. ^ "HUNA INTERNATIONAL - Your best resource for Huna Knowledge and Practice". www.huna.org.
  3. ^ Melville, Leinani (1969). Children of the Rainbow: A Book Concerning the Religion, Legends, and Gods of the Natives of Pre-Christian Hawaii. ISBN 0835600025.

Bibliography