The cycle graph with n vertices is called Cn.
[2] The number of vertices in Cn equals the number of edges, and every vertex has degree 2; that is, every vertex has exactly two edges incident with it.
Among graph theorists, cycle, polygon, or n-gon are also often used.
Their duals are the dipole graphs, which form the skeletons of the hosohedra.
In a directed graph, a set of edges which contains at least one edge (or arc) from each directed cycle is called a feedback arc set.