Answer:
Pretty sure it is B sorry if I am wrong :)
114°
Step-by-step explanation:
<A=<B (corresponding angles)
6x+12=3x+63
6x-3x=63-12
3x=51
Dividing both sides by 3
x=17
Now
<A=6x+12
=6(17)+12
=102+12
=114°
3π/4