Answer: y = 144
because l//m
=> y + x = 180°
but y = 4x (2 vertical angles) => x = y/4
with x = y/4
=> y + y/4 = 180°
⇔ 5y/4 = 180°
⇔ 5y = 180.4 = 720
⇔ y = 720/5 = 144
Step-by-step explanation:
