The Star Polygon , also called the Pentacle, Pentalpha, or Pentangle.
See also Dissection, Hexagram, Hoehn's Theorem, Pentagon, Star Figure, Star of Lakshmi
References
Ogilvy, C. S. Excursions in Geometry. New York: Dover, pp. 122-125, 1990.
Pappas, T. ``The Pentagon, the Pentagram & the Golden Triangle.'' The Joy of Mathematics.
San Carlos, CA: Wide World Publ./Tetra, pp. 188-189, 1989.
Schwartzman, S. The Words of Mathematics: An Etymological Dictionary of Mathematical Terms Used in English.
Washington, DC: Math. Assoc. Amer., 1994.