In primul rand stii ca m(AOB)+m(BOC)+m(COA)=360°.
Deci x°+20°+2x°+3x°-20=360°
6x°=360°
=>x=60°
m(AOB)=x+20=80°
m(BOC)=2x=120°
m(COA)=3x-20=180-20=160°
Sper ca ai inteles.
