Let's say I have a graph like this
How can I prove that this graph is planar(or non-planar)?
According to Kuratowski's theorem: Equivalently, a finite graph is planar if and only if it does not contain a subgraph that is homeomorphic to K5 or K3,3.
So I need to find if this graph containts subgraphs K(5) or K(3,3)?
And if I need to add few edges to make in non-panar, does it mean that I need to add edges to get either subgraph K(5) or K(3,3)?