Find the number of diagonals of a nonagon?

Question: Find the number of diagonals of a nonagon?

There are 27 diagonals of a nonagon. The formula for determining the number of diagonals of an n sided polygon is n(n-3)/2 thus a nonagon has 9 (9-3)/2  = 9(6)2 = 54/2 = 27  diagonals.