Question

the number of diagonals in a septagon is
1)21 2)42 3)7 4)14

Answer 1

Solution :-

To find the number of diagonals in a polygon with 'n' sides, we use the following formula.

n(n - 3)/2

Heptagon is a seven sided polygon. So, here n = 7

⇒ n(n - 3)/2

⇒ 7(7 - 3)/2

⇒ (7*4)/2

⇒ 28/2

⇒ 14

So, there are 14 diagonals in a heptagon.

Option (4) is correct.

Answer 2

Solution :

Option (4) is correct

Given:

n=7 sides (heptagon)

The number of diagonals in a polygon with 'n' sides= n(n - 3)/2

The number of diagonals in a polygon with '7' sides


= 7(7 - 3)/2

= 7×(4)/2

=7×2

=14

Hence,, there are 14 diagonals in a heptagon.

==================================================================

Hope this will help you...