Answer:
40 ft
Explanation:
Draw a diagram. You will see that 50 is the hypotenuse and that the height is 30, and from your scratch work, I can see that you know the Pythagorean Theorem, so I will do the calculations: We have that 30^2 + x^2 = 50^2, or 900 + x^2 = 2500, or x^2 = 1600 so x = 40.