2)<2=70°
180-(70+70)=40
<3=40°
3)(180-90)÷2=45
<1=45°
<2=45°
<3=90°
6)180-40=140
<2=140°
180-(20+140)=20
<1=20°
2)<2=70°
180-(70+70)=40
<3=40°
3)(180-90)÷2=45
<1=45°
<2=45°
<3=90°
6)180-40=140
<2=140°
180-(20+140)=20
<1=20°