Answer:
The correct answer is C.
Explanation:
Angles 1 and 2 have a straight line that is equal to 180 degrees and so does 2 and 3.
So if you split those in half you get the equations:
6z = 90 degrees is 15 degrees
9x = 90 degrees is 10 degrees
and
x + y = 90 degrees is 80 degrees