Planar graph
A planar graph is a type of graph that can be drawn on a flat surface (like a piece of paper) without any of its edges crossing each other (except at the vertices, I suppose).
Planar graph: a graph which can be drawn so that no edges cross.
Euler’s formula
Section titled “Euler’s formula”For any connected planar graph, there is a relationship between the number of vertices (V), edges (E), and faces (F) of the graph:
Where:
= number of vertices = number of edges = number of faces (including the outer, infinite face)
This is Euler’s formula for planar graphs.
Kuratowski’s theorem
Section titled “Kuratowski’s theorem”TODO