Can any guide me to the right answer? It’s not 48 or 48.5

59.8
h = height of girl
cos 39 = adjacent (h) /hypotenuse (77 in)
h = 77 cos 39
h = 59.8 in
You used sin instead of cosine, notice that the angle is placed on the top corner, meaning her height is the length adjacent to the angle, not opposite.