Nomor 6,7,8,9. Makasiii

6. Sudut ABC + DBC = 180°
Maka ABC = 180°- 140 ° = 40°
ABC + BAC +ACB = 180°
40° + (y+10°) + (2y+10°) = 180°
3y+20°= 180° - 40° = 140°
3y = 140° - 20° = 120°
y = 120°/3=40°
BAC = y+10° = 40°+10° = 50° (C)

7. 90°-25°=65° (A)
8.180°-130° = 50° (C)
9.180°-35° = 145° (A)