The name of the polygon is an Octdecagon, or in other words, a 18-sided polygon. You find the total angles of a polygon by the formula (n - 2) * 180. What I did in this case to find the number of sides, was that I divided 2,880 by 180. My quotient was 16. Then, I added 2 in order to get 18. I did the reverse by doing (18 - 2) * 180 to check my answer, and it equaled 2,880.