2013 AMC 10A Problems/Problem 25

Problem

25. All 20 diagonals are drawn in a regular octagon. At how many distinct points in the interior of the octagon (not on the boundary) do two or more diagonals intersect? (A) 49 (B) 65 (C) 70 (D) 96 (E) 128

70-5-16=49, so THE ANSWER IS A