Anonymous

Since each edge connects two vertices, the total of all the degrees = 2 X number of edges = even. If each of 5 vertices has degree 3, the total of the degrees would be 5 X 3 = 15, which is odd. Therefore that's impossible.

Anonymous

True

Anonymous

No. Vertices x Degrees must be even, otherwise one line on the graph doesn't have a terminating end.

Anonymous

Yes, but it will not be a closed or connected graph.