دوضلعی

Also known as 2-gon, demisquare, 2-demicube

In geometry, a bigon, digon, or a '''2-gon''', is a polygon with two sides (edges) and two vertices. Its construction is degenerate in a Euclidean plane because either the two sides would coincide or one or both would have to be curved; however, it can be easily visualised in elliptic space. It may also be viewed as a representation of a graph with two vertices, see "Generalized polygon".