Question

The sum of interior angle of regular polygon is 1440 degree. Find the number of sides of polygon

Answer 1

since interior angles of regular polygon=(2n-4)90
so ,
1440=180n-360
180n=1440+360
n=1800/180=10
so number of sides=10

Answer 2

Ler the number of sides be x

(2n-4)*90= 1440°. {n=number of sides}

180x-360=1440°

180x=1440+360

180x=1800

x=1800/180

x=10

Then number of sides is 10