Planar Graphs

Planar Graph

A planar graph is a graph that can be embedded in the plane, meaning it can be drawn on a flat surface without any edges crossing each other. Formally, a graph $G=(V,E)$ is planar if there exists an injective function $f:V\to {\mathbb{R}}^2$ such that for every edge $uv\in E$, the line segment connecting $f(u)$ and $f(v)$ does not intersect with any other edge’s line segment except at its endpoints.