|Symmetry||I2(2), order 4|
|Vertex figure||Dyad, length 0|
|Measures (edge length 1)|
A digon is a polygon with two sides. It is degenerate if embedded in Euclidean space, as its edges coincide. It can however be thought of as a tiling of the circle. In two-dimensional or higher spherical space, it can form a lune such as the ones making up a hosohedron.