What’s a and b in these 3? 20 points + brainliest

Answer:
1) a 130° - (360 - (50×2)) /2
B 50° - opposite angles
2) a 25° - 90° - 65 = 25 °
B 270° - 360° - 90° = 270°
3) a ) 60° - 180° - 120° = 60° (there are 180° in a straight line)
B) 90° - 180°-90° = 90°