Q. 35.0( 2 Votes )
Write the number of diagonals of an n-sided polygon.
Answer :
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 
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