Răspuns:
AOB+BOC=180
MON=(AOB+BOC):2=180:2=90 grade
Explicație pas cu pas:
a) Daca AOB=60; BOC=120 MON=(60+120):2=90 grade
b) BOC=100; AOB=80; MON=(100+80):2=90grade
c) AOB=a (90) grade; BOC=(180-a); MON=(a-180+a):2=90 grade
2a=270; a=270:2=135; deci AOB =135grade; BOC=45 grade
MON=90 grade