The number twelve has a lot of potential meanings. It is the number of months in the year, thus representing a yearly cycle and its completion and wholeness. It is the number of disciples of Jesus, which makes it a common number in Christianity, and the original number of Hebrew tribes, which makes it a common number in Judaism.

But a twelve-sided figure most commonly represents the zodiac, which is divided into twelve signs.

Those twelve signs are further divided into four groups identified by element (three fire signs, three water signs, etc.), so a dodekagram made up of four overlapping triangles (depicted here) works particularly well. A dodekagram made up of two overlapping hexagons can be used to divide the zodiac symbols by male and female qualities. (You can't overlap hexagrams, since hexagrams are overlapping triangles. It's the same thing as a dodekagram made up of four triangles.)

Read more:Complicated Polygons and Stars