#### Answer

We can determine if a vertex is even or odd by counting the number of edges which are connected to the vertex. This will tell us the degree of the vertex, and we can determine if the vertex is odd or even.
If the degree of a vertex is an odd number, then the vertex is odd. If the degree of a vertex is an even number, then it is an even vertex.

#### Work Step by Step

It is quite simple to determine if a vertex is odd or even.
We can determine if a vertex is even or odd by counting the number of edges which are connected to the vertex. This will tell us the degree of the vertex, and we can determine if the vertex is odd or even.
If the degree of a vertex is an odd number, then the vertex is odd. If the degree of a vertex is an even number, then it is an even vertex.