Answer:
a. 137°
Explanation:
∠1 and ∠8 are corresponding angles. They are in the same relative position with respect to the parallel lines and the transversal.
Then, corresponding angles have the same measure, so:
∠8 = ∠1
∠8 = 43°
Now, ∠8 and ∠6 form a straight line, so the sum of these angles is 180°. Therefore, the measure of ∠6 can be calculated as:
∠6 = 180 - ∠8
∠6 = 180 - 43
∠6 = 137°
So, the answer is a. 137°
