Answer:
See below because you don't specify if they are complementary or supplementary angles
Step-by-step explanation:
Solution if supplementary:
12x+12+15+3x+18=180
15x+45=180
15x=135
x=9
m<A=12(9)+12=108+12=120 degrees
m<C=3(9)+18=45 degrees
Solution if complementary:
12x+12+15+3x+18=90
15x+45=90
15x=45
x=3
m<A=12(3)+12=48 degrees
m<C=3(3)+18=27 degrees