Write the number of diagonals of an n-sided polygon.

An n-sided polygon has n vertices.

By joining any two vertices of the polygon, we obtain either a side or a diagonal of the polygon.

Number of line segments obtained by joining the vertices of an n-sided polygon if we take two vertices at a time, number of

Ways of selection 2 out of n = nC2

Out of these lines, n lines are sides of the polygon.

Number of diagonals of the polygon =

nC2 – n – n

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Permutations & Combinations | Analyze your learningFREE Class
Challenging Quiz on P&C | Test Yourself55 mins
Understand Permutations like never before60 mins
Check Your progress Part 2| Interactive Quiz: Permutation & Combination54 mins
Lecture on Combinations49 mins
Interactive Quiz on Division and distribution of objects17 mins
Interactive Quiz on Combinations50 mins
Lets see how good you can manage numbers | P&C Quiz Challenge41 mins