m
a. 25.5
b. 51
c. 129
d. 31

Answer: A) 25.5
Step-by-step explanation:
Make Angles AFB and CFD = x. Then, because Angle AFD is 90 and Angle BFC is 39;
90-39=2x
51 = 2x
15.5 = x
Hope it helps <3