Вся окружность =360°
1) 2/5*360=144°
144:2=72°
2) 4/15*360=96°
96:2=48°
3) 7/12*360=210°
210:2=105°
4)5/9*360=200°
200:2=100°
5)13/18*360=260°
260:2=130°
6)17/20*360=306°
306:2=153°
7)23/30*360=276°
276:2=138°
Вся окружность =360°
1) 2/5*360=144°
144:2=72°
2) 4/15*360=96°
96:2=48°
3) 7/12*360=210°
210:2=105°
4)5/9*360=200°
200:2=100°
5)13/18*360=260°
260:2=130°
6)17/20*360=306°
306:2=153°
7)23/30*360=276°
276:2=138°