Answer:
m∠BCA = m∠B'C'A'
Step-by-step explanation:
The angle that is being discussed is always the letter in the middle. The other two letters help you find the point if it is connected to more than one angle.
C, when transformed, became C'. This is the same for the other two letters:
A -> A'
B -> B'
C -> C'
The correct answer must have the same letter in the middle.
m∠BCA = m∠B'C'A' is the only answer with the same letter in the middle.
