Sum of angles of a triangle to zero. For a spherical triangle, the sum of the angles is greater than 180° and can be up to 540°. Specifically, the sum of the angles is where "f" is the fraction of the sphere's area which is enclosed by the triangle. Note that spherical geometry does not satisfy several of Euclid's axioms (including the parallel postulate.) Angles between adjacent sides of a triangle are referred to as "interior" angles in Euclidean and other geometries. "Exterior" angles can be also defined, and the Euclidean triangle postulate can be formulated as the exterior angle theorem. One can also consider the
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