Maths question PLS HELP?

With a 15 sides polygon, we have 30 exterior angles. The sum of all these triangles would be 180 x15= 2700 degrees in total. The total for the interior would only be 360 degrees. So, 2700-360 = 2340 will be the balance.for exterior angles. Since they are all equilateral triangles we divided 2340 by 30 and we get 78 degree each. Final Answer : Each exterior angle is 78 degree.