Monogon
In geometry, a monogon, also known as a henagon, is a polygon with one edge and one vertex. It has Schläfli symbol. Since a monogon has only one side and only one vertex, every monogon is regular by definition.In Euclidean geometry a monogon is a degenerate polygon because its endpoints must coincide, unlike any Euclidean line segment. Most definitions of a polygon in Euclidean geometry do not admit the monogon.In spherical geometry, a monogon can be constructed as a vertex on a great circle. This forms a dihedron,, with two monogonal faces which share one 360° edge and one vertex. Its dual, a hosohedron, has two antipodal vertices at the poles, one 360 degree lune face, and one edge between the two vertices.
Monogonal dihedron, |
Monogonal hosohedron, |
