出典:Wiktionary
出典:Wikipedia
出典:『Wikipedia』 (2010/05/05 15:20 UTC 版)
In geometry, the semiperimeter of a polygon is half its perimeter. Although it has such a simple derivation from the perimeter, the semiperimeter appears frequently enough in formulas for triangles and other figures that it is given a separate name. When the semiperimeter occurs as part of a formula, it is typically denoted by the letter s.