We know that line GJ bisects the angle FGH, that means we also know that the angle FGH is divided into two equal sizes.
Now, we have
Angle FGJ = Angle HGJ
Angle GJF = Angle GJH
This information means that angle GHJ = angle GFJ
We have two congruent right-angled triangle
We can then further deduce that
Side GF = Side GH
[tex]3x-8=16[/tex]
[tex]3x=16+8[/tex]
[tex]3x=24[/tex]
[tex]x=8[/tex]
Since triangle FGJ and triangle GJH are congruent, then side FJ equals to side JH
Hence, the length of FH = 2×8=16
