Answer:
C. 85
Step-by-step explanation;
You know that that sum of the angle measures in a quadrilateral is 360°, so you can solve for the missing angle measure.
So, you can see the bottom left corner equals 90 degrees because of the right angle. The other degrees plus 90 equals 275. So we would subtract 275 from 360 and get 85.
This means that "1" equals 85 degrees.
I hope this helps!