The dyad,[1] ditelon, dion[2] or simply line segment, is the only possible 1-polytope (rarely polytelon). Its facets are two points. It appears as the edges of all higher polytopes.

Dyad
Line segment.svg
Rank1
TypeRegular
SpaceSpherical
Notation
Bowers style acronymDyad
Coxeter diagramx (CDel node 1.png)
Schläfli symbol{}
Tapertopic notation1
Toratopic notationI
Bracket notationI
Elements
Vertices2
Vertex figurePoint
Measures (edge length 1)
Circumradius
Length1
Central density1
Number of external pieces2
Level of complexity1
Related polytopes
ArmyDyad
DualDyad
ConjugateNone
Abstract & topological properties
Flag count2
Euler characteristic2
OrientableYes
Properties
SymmetryA1, order 2
ConvexYes
NatureTame

A dyad is simultaneously the 1-simplex, the 1-hypercube, and the 1-orthoplex. Furthermore, a dyad is the pyramid, prism, tegum, ditope, and hosotope of the point. It may also be considered a 0-hypersphere.

Congruent dyads can tile 1D space as the regular apeirogon.

Vertex coordinatesEdit

Coordinates for the vertices of a line segment of length 1 are simply the points:

  •  

RepresentationsEdit

The dyad has two distinct representations:

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

ReferencesEdit

  1. Bowers, Jonathan. "Regular Polytela and Other One Dimensional Shapes".
  2. Johnson, Norman W. Geometries and transformations. p. 224.

External linksEdit