Answer
3/5=x/4
x=20/3
Explanation
If we assume that triangle EGH is similar to triangle EFG than side EG in the smaller triangle corresponds to side EF in the larger triangle and also side GH (x) corresponds yo side GF so 3/5=x/4 and then we cros multiply
3x=4*5
3x=20
x=20/3
