Question

any connected graph with n vertics and n-1 edges is a tree.​

Answer 1

Answer:

I can't type it........

Answer 2

Answer:

with a, b and c being vertices, and {a,b}, {b,c} being edges.

Is there some way to prove this logically?

--UPDATE--

Does this look correct? Any advice on how to improve this proof would be appreciated. Thank you.