ExplanationThe sum of the interior angles of a polygon, use 180(n − 2), where n is the number of sides: Sum of the interior angles = 180(9 − 2) → 180(7) → 1260°.

Since this 9-sided figure is regular, all of the interior angles are equal: 1260° \(\div\) 9 = 140°.

Now we can find x:

x° + 140° = 180°

x = 40° Hence the value 40 is correct.Attachment:

di new.jpg [ 39.94 KiB | Viewed 11978 times ]
_________________

Sandy

If you found this post useful, please let me know by pressing the Kudos Button

Try our free Online GRE Test