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
The Pentagon late 1960s to ferry personnel between Bolling Air Force Base and the Pentagon. The main entrance for visitors is on the southeast side, as are the Pentagon Metro station and the bus station. There is also a concourse on the southeast side of the second floor of the building, which contains a mini-shopping mall. The south parking lot adjoins the southwest facade, and the west side of the Pentagon faces Washington Boulevard. The concentric rings are designated from the center out as "A" through "E" (with in addition "F" and "G" in the basement). "E" Ring offices are the only