Answer:
∠4=135
Step-by-step explanation:
vertical angles are always equal
∠1=∠3
3x-9=x+27
3x-x=27+9
2x=36
x=36/2=18
∠1 =3x-9
∠1=3(18)-9
∠1=54-9=45
∠1+∠4=180 degrees
45+∠4=180
∠4=180-45