4) В=А
В=70°
С= 180-(70+70)=40°
С = 40°
9) М=180-130=50°
К=М
К=50°
N= 180-(50+50)=80°
N=80°
28) B=180-(80+60)=40°
C=180-60=120°
B=D
B=D=(180-120): 2= 30°
B=30°; D= 30°
4) В=А
В=70°
С= 180-(70+70)=40°
С = 40°
9) М=180-130=50°
К=М
К=50°
N= 180-(50+50)=80°
N=80°
28) B=180-(80+60)=40°
C=180-60=120°
B=D
B=D=(180-120): 2= 30°
B=30°; D= 30°