помогите пожалуйста геометрия 9 класс

А = n-2/n 180
1) n = 3
a = 3-2/3 180 = 180/3 = 60
2) n = 4
a = 4-2/4 180 = 2/4 180 = 1/2 180 = 180/2 = 90
3) n = 5
a = 5-2/5 180 = 3/5 180 = 3 36 = 108
4) n = 6
a = 6-2/6 180 = 4/6 180 = 4 30 = 120
5) n = 10
a = 10-2/10 180 = 8/10 180 = 8 18 = 144
6) n = 18
a = 18-2/18 180 = 16/18 180 = 16 10 = 160