Answer:
A
Step-by-step explanation:
10 and 8 are equal
11 and 15 are equal
due to the fact that the angles 10 and 11 but also 8 and 15 are supplementary, we know that they add up to be 180 degrees
180-42=138 degrees
and this means that angle 8 will also be 138 because of what we established earlier
