Answer: 9°
Step-by-step explanation:
(3w + 7)° + 90° + (7w - 7)° = 180°
=> 3w + 7 + 90 + 7w - 7 = 180
=> 10w + 90 = 180
=> 10w = 180 - 90 = 90
=> w = 90 / 10 = 9°
