Answer:
A
Step-by-step explanation:
First, we know that angles 6 and 8 are supplementary.
Therefore m∠6 + m∠8 = 180°
123.5° + m∠8 = 180°
m∠8 = 56.5°
Then, using the alternating exterior angle theorem, we can find that...
m∠8 ≅ m∠1
So m∠1 = 56.5°
the answer to this question is A
