digon

Definitions

1. A polygon having two edges and two vertices.
2. A pair of parallel undirected edges in a multigraph.
3. A pair of antiparallel edges in a directed graph.

Equivalents

Examples

“They [the students] also came upon new and unusual mathematical figures: the digon, a two-sided polygon on a spherical space, and the apeirogon, an open⟳ polygon with infinitely many sides […]. All these discoveries brought up even more questions. Is a circle a polygon? What makes an octagon an octagon – its eight vertices, its eight sides, or both? Can a polygon cross itself? Does a polygon need⟳ to be closed?”

CEFR level