Definition:Incident (Graph Theory)/Planar Graph

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 $$A, B, H, C$$.