Find the number of diagonal in hexagon.

Given: A hexagon.

To do: To find the number of diagonals in a hexagon.

Solution:

 Number of diagonals in a polygon$=\frac{n( n-3)}{2}$, here $n=$Number of sides of the polygon.

We have a hexagon, therefore $n=6$

$\therefore$ Number of diagonals in a hexagon$=\frac{6( 6-3)}{2}=9$

Thus, number of diagonals in a hexagon is $9$.