The sum of the interior angles of a polygon is (n-2)*180, n being the number of sides.
a nonagon has nine sides, so the total of interior angles is (9-2)*180=7*180
this is a regular nonagon, so each interior angle has the same degrees:
7*180/9=7*20=140
the exterior angle=180-the interior angle=180-140=40
40 is the correct answer.
The best way to remember which place is rounded to the nearest 10th, 100th, 1000th, etc., is by counting the number of 0's.
This question wants you to round to the nearest 10th.
How many 0's does 10 have? 1.
So we round one space after the decimal.
This gets us 73.2