ABK + BEF = 180°
2ABK = 3BEF =>ABK = 3BEF/2
3BEF/2 + BEF = 180
3BEF + 2BEF = 360
5BEF = 360
BEF = 72°
ABK = 108°
DEL = BEF = 72°
CBK = 180° - ABK = 72°
pozaaaaaaaaaaaaaaa.....
