Answer :
For a polygon with n sides, the interior angles add up to:
(n - 2) x 180
an octagon has 8 sides:
(8 - 2) * 180 = 6 * 180 = 1080
from the question,1 side measures 2x while 7 sides measure x. this means
7x + 2x = 1080
9x = 1080
x = 1080/9
x = 120°
if x=120°
2x=2(120°)=240°
so, the seven smaller angles are 120°. while the one larger angle is 240°