Ajutor !!! Va rog am nevoie !!! Cat mai repede posibil !!

2)∡COA=180°-40°=140°
∡AOM=40°:2=20°
∡COM=∡C0A+AOM=140+20=160°
3)∡AOD=∡BOC=30°=>∡DOB=∡AOC=180°-30°=150°<=>D,O,C-coliniare