Pentagon Pentagon In geometry, a pentagon (from the Greek πέντε "pente" and γωνία "gonia", meaning "five" and "angle") is any five-sided polygon or 5-gon. The sum of the internal angles in a simple pentagon is 540°. A pentagon may be simple or self-intersecting. A self-intersecting "regular pentagon" (or "star pentagon") is called a pentagram. A "regular pentagon" has Schläfli symbol {5} and interior angles are 108°. A "regular pentagon" has five lines of reflectional symmetry, and rotational symmetry of order 5 (through 72°, 144°, 216° and 288°). The diagonals of a convex regular pentagon are in the golden ratio to its
Victims of Terrorist Attack on the Pentagon Memorial memorial himself. He drew inspiration from the memorial to the 253 dead of the United States Coast Guard ship USS "Serpens", which is located in the northern corner of Section 34 at Arlington National Cemetery. The "Serpens" memorial is octagonal in shape and lists the names of the dead on its side panels. The Victims of Terrorist Attack on the Pentagon Memorial is a pentagonal granite marker high. On five sides of the memorial along the top are inscribed the words "Victims of Terrorist Attack on the Pentagon September 11, 2001". Aluminum plaques, painted black, are inscribed with the names