Number of Diagonals in a Polygon
How many diagonals are there in a polygon?
Depends on the number of sides the polygon has.
The number of diagonals in a polygon depends on the number of sides it has. To compute the number of diagonals, the formula D = n(n-3)/2 is used, where D is the number of diagonals and n is the number of sides in the polygon. An n-sided polygon has n vertices, from which can be drawn n-3 diagonals, but you must divide the expression by 2 because each diagonal would be drawn twice.