View source for 9.7 Problem 24 MA375Fall2008walther - Rhea

Theorem 2 (Kuratowski) says that a graph is nonplanar if and only if it contains a subgraph homeomorphic to <math> K_{3,3} </math> or <math> K_{5} </math>.<br>
Looking at the given graph it is obvious to see that it contains a subgraph homeomorphic to <math> K_{5} </math>.  Therefore, the given graph is nonplanar.<br><br>
--[[User:Aoser|Aoser]] 16:59, 5 December 2008 (UTC)