Answer:
18
Explanation:
We can safely assume EGF and EGD are congruent by SAS (EG = EG reflexive property, and the angle and side given)
that must mean FG AND GD are congruent (CPCTC)
3a = a+6
2a = 6
a = 3
plug this into 3a+a+6 (DF is the sum of the two segments)
4a+6
4(3)+6
18