Dyad

The dyad, ditelon, dion or simply line segment, is the only possible polytelon. Its facets are two points. It appears as the edges of all higher polytopes.

It is the one-dimensional simplex, the one-dimensional hypercube, and the one-dimensional orthoplex. It is also the one-dimensional omnitruncated simplex, along with the 1D version of just about any series of general polytopes.

Identical dyads can tile 1d space in the regular apeirogon.

Vertex coordinates
Coordinates for the vertices of a line segment of length 1 are simply the points:
 * (±1/2).

Representations
The dyad has two distinct representations:


 * x (full symmetry, vertices are the same)
 * oo&#x (vertices considered of different types)