D, because after being reflected onto itself or turning 180 degrees, you would be transforming onto itself. I hope this helps!
Answer:
I think the answer is 81.
Step-by-step explanation:
Vertical angles are congruent.
x + 3 = 84
- 3 = -3
--------------
x = 81
No able engles? Don’t know if i spelt that right but
