Answer: 289 ft.
Explanation:
You can form a right triangle with these features:
1) Base = adjacent-leg = 500 feet
2) angle between the hypotenuse and the base = 30° ( I use 30° instead of 30', because 30' does not make sense, it is a too small angle)
3) Height = opposite-leg = height of the Statue of LIberty = x
Now, use the equation for the trigonometric ratio tangent:
tan(angle) = opposite-leg / adjacent-leg
=> tan (30°) = x / 500ft
=> x = 500ft * tan(30°)
x = 288.67 ft which rounded to the nearest foot is 289 ft.