Question

The sum of the interior angles of a polygon is five timers the sum of its exterior angles. Find the number of sides in the polygon.

Answer 1

Sum of interior angle = $5\times$ sum of exterior angle

Find number of side in polygon

$\to$ for polygon sum of exterior angle is always = ${360}^{\circ }$

Sum of interior angle = $5\times 360$

$={1800}^{\circ }$

let n number of side

$(n-2)180=1800$

$n-2=10$

$n=12$ sides