Răspuns:
Explicație pas cu pas:
∡ AOB= ∡AOM+∡MON +∡NOB
160°=2x+30+2x+x
130=5x⇒ x=26
∡ BON= x= 26°
∡MON= 2x=2·26=52°
∡MOA=2x+30=52+30= 82°
∡BOM= ∡BON+∡NOM=26+52=78°
∡AON= ∡AOM+∡MON= 82+52=134°