Final answer:
In the given rhombus, the length of HF is 26.
Step-by-step explanation:
First, we need to remember that in a rhombus, all four sides are congruent. So, GE = DH = 42. Since GE = 42, we can find HF by subtracting DH from GE. So, HF = GE - DH = 42 - 16 = 26.