Digon

In geometry, a digon  is a polygon with two sides (edges) and two corners (vertices). In Euclidean space, the two sides would have to be on the exact same area, giving the digon zero area. One or both sides could be curved instead, but then it would not be a polygon. This means the digon is said to be degenerate.

However, a digon can be drawn in elliptic space (where all points are on the outline of a circle) by placing the two vertices at opposite sides. Here, the digon's sides are between the vertices. The inside part of the circle means that the digon is not degenerate. A digon can also be drawn on a sphere as a pair of 180 degree arcs connecting antipodal points, when it forms a lune.

A digon must have both sides the same length, and both its angles must be the same measure. This means all digons must be regular polygons. The digon is the simplest abstract polytope in two dimensions.

A digon is represented by Schläfli symbol {2}. A truncated digon, t{2} is a square, {4}. An alternated digon, h{2} is a monogon, {1}.

Category:Shapes
Category:Polygons