Answer: 6
Step-by-step explanation:
1. As 27 degrees is a central arc, we know the angle DFC is 27 degrees too.
2. We know angle EFD is a 90-degrees angle because of the symbol.
3. Add the two angles together and you will get 117.
4. Angles EFD and angles AFB are vertical angles, so angle AFB also equals 117 degrees.
5. Because arc AB is a central arc, we know that 21x-9 = 117.
6. We add 9 to both sides and we get 21x = 126.
7. Divide 21 by both sides and you will get your answer: x = 6.
HOPE THIS HELPED YOU!
