Answer: angle EFB = 35 degrees
========================================================
Explanation:
To get angle EFC, we will average the two arc measures given
This means we add them up and divide by 2
angle EFC = (arcEC + arcBD)/2
angle EFC = (164+126)/2
angle EFC = 290/2
angle EFC = 145
Then we can say:
(angle EFB)+(angle EFC) = 180 ... the two angles are supplementary
(angle EFB) + (145) = 180
angle EFB = 180-145
angle EFB = 35
