Question

how many sides does a regular polygon have if each of its interior angle is 140°

Answer 1

as formula for each interior angle of regular polygon is ( 2n-4)*90/n { where n is no of sides}

140= ( 2n-4)*90/n

140 n=180 n-360

360=180 n-140 n;

360=40n

n= 9 ( nonagon )