Digon

In <a href="/facts/Geometry/wTQf5ffQ">geometry</a>, a bigon, digon, or a 2-gon, is a <a href="/facts/Polygon/yAq7RjPz">polygon</a> with two sides (<a href="/facts/Edge_(geometry)/3lFN6sEz">edges</a>) and two <a href="/facts/Vertex_(geometry)/ID3cea9z">vertices</a>. Its construction is <a href="/facts/Degeneracy_(mathematics)/BqhqlXPH">degenerate</a> in a <a href="/facts/Euclidean_plane/tAUtRFcn">Euclidean plane</a> because either the two sides would coincide or one or both would have to be curved; however, it can be easily visualised in <a href="/facts/Elliptic_space/oMnFAoVb">elliptic space</a>. It may also be viewed as a representation of a <a href="/facts/Graph_theory/VVPCd4TX">graph</a> with two vertices, see "<a href="/facts/Generalized_polygon/ehKVCuyl">Generalized polygon</a>".
A regular digon has both angles equal and both sides equal and is represented by <a href="/facts/Schl%C3%A4fli_symbol/jNQR77UU">Schläfli symbol</a> {2}. It may be constructed on a <a href="/facts/Spherical_geometry/WGLQb1Ys">sphere</a> as a pair of 180 degree arcs connecting <a href="/facts/Antipodal_point/2V3228jA">antipodal points</a>, when it forms a <a href="/facts/Spherical_lune/SLQJJHUU">lune</a>.
The digon is the simplest <a href="/facts/Abstract_polytope/awkKfRGM">abstract polytope</a> of rank 2.
A <a href="/facts/Truncation_(geometry)/DYb589Je">truncated</a> digon, t{2} is a <a href="/facts/Square/JHJeMvmL">square</a>, {4}. An <a href="/facts/Alternation_(geometry)/H2nVs4xj">alternated</a> digon, h{2} is a <a href="/facts/Monogon/gx05DD40">monogon</a>, {1}.

Digon open-in-new

Digon