Thread: Graph Theory question about trees

Ok so I am trying to prove by induction that If T is a tree with 3 or more vertices then T has a vertex that is not a leaf.

I got my P(1) step, but I am getting strung up when I try to go for my
p(n) => p(n+1) step.

any help would be greatly appreciated.

Consider cases of two and three vertices also as the base case. For bigger trees, if one has a non-leaf vertex and adds another vertex and an edge, can become a leaf?