Răspuns:
Explicație pas cu pas:
a)_∡AOB=∡BOC=∡COA
∡AOB=360°:3=120°
b) ∡AOB=90° ∡BOC=∡COA=(360-90)/2=270/2=135°
c)∡BOC=20+∡AOC ∡AOC=∡BOC-20°
∡BOC=∡COA-20° ∡COA=∡BOC+20°
∡BOC-20°+∡BOC+∡BOC+20°=360°
3∡BOC=360° ⇒∡BOC=120°
∡AOC=120-20=100°
∡COA=∡BOC+20°=140°
d) x-1, x,x+1
3x=360° x=120°
119°, 120°, 121°
3x+3