Answer:
10. x=15 degrees
11. x=10 degrees
Explanation:
For these triangles inscribed in the circle, the top angle is always 90 degrees. Because of this, we can subtract 90 degrees from 180 degrees and be left with 90 degrees. For problem 10, 30+4x=90, so x=15. For problem 11, 4x+5x=90, so x=10