Answer:
D
Step-by-step explanation:
You can't be certain unless this figure is a square or a rectangle. The question should state what it is.
You are asked for HF in the question. I think you are given JG. Diagonals of a square or rectangle are equal and bisect each other.
HJ = GJ From the above statement.
2HJ = HF HF is bisected.
2*15 = 30
HF = 30
