Răspuns:
Explicație pas cu pas:
b. BOC+COD+DOA+AOB=360°
=> x+30+2x+20+x+3x-40=360
7x=360-10
x=50
c. AOB= x+30=50+30= 80°
BOC=2x+20= 100+20=120°
COD=x=50°
DOA=3x-40= 150-40=110°
d.[tex]\frac{BOC}{2\\}[/tex]+[tex]\frac{COD}{2}[/tex]= [tex]\frac{120}{2}[/tex]+[tex]\frac{50}{2}[/tex]= 60+25= 85°
