Draw a picture first. My idea is: because angle C is greater than angle B and line AB is greater than line AC (big angle versus big side), line AE is on the left side of the triangle. Draw a picture and analyze it. I don't draw now. Let's put it this way: because the angle FED is the outer angle of the triangle ABE, the angle FED= the angle B+ the angle BAE, and because FD is perpendicular to BC and D, the angle FDE is a right angle. So EFD angle =90 degrees, that is, EFD angle =90 degrees, (angle B+ angle BAE). Because AE bisects angle BAC, angle BAC=2 angle BAE. Then, by using the theorem of triangle interior angle sum, it is obtained that angle B+ angle C+ angle BAC= 180 degrees. Substituting the previous conclusions: Angle B+ Angle C+2 Angle BAE= 180 degrees, Angle BAE=90 degrees-1/2 (Angle B+ Angle C), so Angle EFD=90 degrees-[Angle B+90 degrees-1/2 (Angle B+)