Answer:
46.2 feet
Explanation:
In the right triangle model, you are given the angle, the adjacent side, and you want to find the opposite side. The relevant trig relation is ...
Tan = Opposite/Adjacent
tan(57°) = height/(30 ft)
Multiplying by the denominator gives ...
height = (30 ft)tan(57°) ≈ 46.2 ft
The height of the tree is about 46.2 feet.