Question 382094
We can use the fact that the sum of the exterior angles is always 360.

If the interior angle is 168, then the exterior angle is 180 - 168, or 12. The 360 degrees is evenly distributed over all of the angles, so 360/12 = 30 sides.

The formula for the sum of the angles in an n-sided polygon (in degrees) is 180(n-2). To find the average measure of one angle, divide by n.