For question 1, I said that the graph is connected because for every pair of distinct vertices there is a path between them. There is a simple path between every pair of distinct vertices of the connected undirected graph.
For question 2, I said the graph is not a tree because it has may simple circuits in the graph, for example, A, B, C, A, or A,B,D,E,F,C,A or F,C,B,D,E,F etc.
What my real question is that I am worried that I wont get the full marks. There must be a way to mathematically explain this, e.g. for every n vertices.....something along the lines of that. Could you show me how?
