Answer:
D
Step-by-step explanation:
∠1 + ∠2 = 180 {Supplementary angles}
6x + 15 + 3x + 3 = 180
6x + 3x + 15 + 3 = 180
Combine like terms
9x + 18 = 180
Subtract 18 from both sides
9x = 180 - 18
9x = 162
x = 162/9
x = 18
∠2 = 3x +3
= 3*18 + 3
= 54 + 3
∠2 = 57°
