Math B question(givin 10 pts away it is EZ!!)?

Question

If line BA bisects a.prove that m b. Find the number of degrees in

Please try to put the answer in like statement-reason form thanks so much!!
~*God-Bless*~

Here is the diagram:
http://i23.photobucket.com/albums/b380/beyonce4real/problem11.jpg

Answer 1

a. By the exterior angle theorem, angle fbd is equal to angle C plus angle D. Since Ray BA bisects angle FBD, angle ABD is equal to angle FBA; however, since angle ABD is equal to angle D, angle FBA has to be equal to angle C.

Since angle FBD= angle C+ angle D (exterior angle theorem)
and angle FBD= angle (FBA + ABD)= angle (C+D); but since angle ABD=angleD, angle FBA=angle C.

b. By part A, 3x+20=x+40 so 2x=20 x=10
Therefore, angle abf is equal to 50 degrees.

Answer 2

If its easy, why are you asking?

Ana