Hexagram

A hexagram is a six-pointed star, with all lines the same length and all angles the same.  A 'hexangle', 'star hexagon', or 'hexalpha' means the same thing.Graham, Dr. O.J. 2001. The Six-Pointed Star: its origin and usage. 4th ed, Toronto: The Free Press, . 
It is used in historical, religious and cultural contexts, for example in Hanafism,Miller, Sam 
 2010. Delhi: Adventures in a Megacity, page 91. Judaism, Hinduism and occultism. It is possible that this simple geometric shape, like the triangle, circle, or square, has been created by various peoples with no connection to one another.

Group theory
In mathematics, the root system for the simple Lie group G2 is in the form of a hexagram, with six long roots and six short roots.
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 Construction by compass and a straight edge 
A six-pointed star, like a regular hexagon, can be created using a compass and a straight edge:
Make a circle of any size with the compass.
Without changing the radius of the compass, set its pivot on the circle's circumference, and find one of the two points where a new circle would intersect the first circle.
With the pivot on the last point found, similarly find a third point on the circumference, and repeat until six such points have been marked.
With a straight edge, join alternate points on the circumference to form two overlapping equilateral triangles.

References

Category:Symbols
Category:Religious symbols