Definition:Incident (Graph Theory)/Planar Graph

Definition
Let $G = \left({V, E}\right)$ be a planar graph:


 * PlanarGraph.png

Then a face of $G$ is incident to an edge if the edge is one of those which surrounds the face.

Similarly, a face of $G$ is incident to a vertex if the vertex is at the end of one of those incident edges.

In the above graph, for example, the face $ABHC$ is incident to:
 * the edges $AB, BH, HC, CA$;
 * the vertices $A, B, H, C$.