Răspuns :
y+150°=180°
y=30°
2x+20=150°
2x=130°
x=65°
b)x+15°=40°
x=40°-15°
x=25°
3y+10°=40°
3y=30°
y=10°
y=30°
2x+20=150°
2x=130°
x=65°
b)x+15°=40°
x=40°-15°
x=25°
3y+10°=40°
3y=30°
y=10°