jawablah pertanyaan berikut...

Maaf kalau salah...ini hasil hitunganku

7. 3x+5x+10x=180°
   18x=180°
x=180°/18
x=10°
q=5×10°=50°

8. 5x+30°+6x+2x+20°=180°
  13x+50°=180°
13x=180°-50°
x=130°/13=10°
A=5x+30=5×10+30=80°

9. 3x+10+4x+20+3x=180°
   10x+30°=180°
10x=150°
x=150°/10=15°
3x+sdtB=180°
 3×15°+B=180°
B=180°-45°
b=135°