1) m(AOB) +m(BOC) +m(COA) =360 grade
m(AOB) =m(BOC)-40
m(COA) =m(BOC)/2
Deci relatia 1 devine: m(BOC)-40+m(BOC) +m(BOC)/2=360
2m(BOC) +m(BOC)/2 =400 grade
5m(BOC)/2 =400 grade
m(BOC) =800/5 =160 grade
m (AOB) =160-40 =120 grade
m(COA) =m(BOC)/2 =160/2 =80grade