A nonagon is a polygon with nine sides and nine angles. The term derives from the Latin "nona" meaning nine and the Greek "gonia" meaning angle. In a regular nonagon, all sides and angles are equal, and each internal angle measures 140 degrees. Nonagons can be found in various geometric and architectural designs, as well as in art.
For a nine-sided enclosed object, a nonagaon, the equation would be 360 degrees divided by 9. That will provide you with the answer.
The formula for an exterior angle is 180-(180/n)(n-2) where n is the number of sides. For a nonagon the number of sides is 9. Plugging this into the equation gives: 180-(180/9)(9-2) =180-(20)(7) =40 So the exterior angles of a regular nonagon will measure 40 degrees.