tentukan nilai x pada gambar dibawah ini

1. a) 180° = 165° + x <=> 180°-165° = x <=> 15°=x
b) 180° = 105° + x <=> 180° - 105°= x <=> 75° = x
c) 180° = 150 + 3x <=> 180°-150° = 3x <=> 30°/3 =x <=> 10° = x

2. A.y=90°-15°
y =75°
B. 180° = 90° + 18° + y
y = 180°-98°
y = 82 °