In graph theory, an undirected graph is an **outerplanar graph** if it can be drawn in the plane without crossings in such a way that all of the vertices belong to the unbounded face of the drawing. That is, no vertex is totally surrounded by edges. Alternatively, a graph *G* is outerplanar if the graph formed from *G* by adding a new vertex, with edges connecting it to all the other vertices, is a planar graph.

Read more about Outerplanar Graph: History, Forbidden Graph Characterizations, Biconnectivity and Hamiltonicity, Coloring, Related Families of Graphs, Other Properties

### Famous quotes containing the word graph:

“In this Journal, my pen is a delicate needle point, tracing out a *graph* of temperament so as to show its daily fluctuations: grave and gay, up and down, lamentation and revelry, self-love and self-disgust. You get here all my thoughts and opinions, always irresponsible and often contradictory or mutually exclusive, all my moods and vapours, all the varying reactions to environment of this jelly which is I.”

—W.N.P. Barbellion (1889–1919)