Find the number of diagonals that can be drawn by joining the angular points of a heptagon.

Find the number of diagonals that can be drawn by joining the angular points of a a polygon of 20 sides.

Find the number of diagonals that can be drawn by joining the angular ponts of decagon .

The number of diagonals that can be drawn by joining the vertices of an octagon is a. 20 b. 28 c. 8 d. 16

Number of triangles that can be formed by joining the 10 non-collinear points on a plane is

Find the number of triangles which can be formed having vertices at angular points of a convex polygon of m sides.

Find the number of diagonals of a 16-sided polygon.

Find the number of straight lines that can be drawn through any two points out of 10 points, of which 7 are collinear.

The number of lines that can be drawn thorugh a given point is

Find the numbers of diagonals in the polygon of n sides.

Find the number of diagonals in the convex polygon of n sides .