What I meant was 1:1. Diagonals AC, AD, BD, BE, CaA, CE. Each of the five vertices has 2 non-neighboring vertices so 2 distinct diagonals can be defined with respect to any vertex. But AC and CA are the same diagonal. So there are 5 distinct diagonals and 5 interior angles. That defines a ratio of 1:1 between the number of angles and the number of diagonals in a pentagon. (This is not a general result for polygons. A square has 2 diagonals, but 4 interior angles. A hexagon has 3 or 9 diagonals, depending on how we define diagonal, but 6 interior angles.)You're referring to what JeffM said in post #10, right?
I have no idea what he meant.
I shall correct my original post. Failed to proof carefully. Apologies to all.