This is the answer the picture below hope this help
Start with x:
Since x and 57º make a straight line, x+57 = 180 (because a line is 180º). This says x=123º
Now for y:
Because lines m and n are parallel, y and 57º are alternate interior angles and have the same measure. y=57º
Finish with z:
Since y and z make a straight line, can you finish that one from here?
The formula for an infinite geometric sequence is the following:

Just substitute the values of

and r into the formula.



Therefore, the answer is 20.
I believe the answer would be c