9514 1404 393
Answer:
x = 6
Explanation:
Angles AFB and CFE are vertical angles, so have the same measure. That means arc AB has the same measure of arc CE. The latter arc is 27° more than arc DE, which is 90°. So, we have ...
arc AB = arc CE
21x -9 = 90 +27
21x = 126 . . . . . . add 9, collect terms
x = 6 . . . . . . . divide by 21