Question

Sum of interior angle of a regular polygon is equal to six times the sum of exterior angle. Find the no. of sides.

Answer 1

Let a be the sum interior angle of regular polygon

sum of exterior angles of polygon $=360$

$a=6\times 360$

$a={2160}^{\circ }$

sum of interior angle $=2160$

$(n-2)\left(180\right)=1260$

$n-2=12$

$n=14$

$\therefore$ no. of sides $=14$