If the sum of number of sides and diagonals of a polygon is 78, then the number of diagonals is equal to

The number of diagonals of a polygon of 15 sides is:

If a polygon has 8 sides, then the number of diagonals of the polygon is _____.

Find the number of diagonals of a polygon of 10 sides.

In a polygon,no three diagonals are concurrent.If the total number of points of intersection of diagonals interior to the polygon is 70 ,then the number of diagonals of the polygon is a.20 b.28 c.8 d.none of these

The number of diagonals in a 27 - sided polygon is

Find the number of diagonals of a polygon of 20 sides

If a polygon has 6 sides, then the number of diagonals of the polygon is _______