Answer:
x = 12.489996 ft
Explanation:
In order to solve one side length of a right triangle given two of other side lengths, you can use the pythagorean theory.
The theory states that the sum of the two adjacent side squares equals the square of the hypotenuse.
Basically:

Since the problem gives you the hypotenuse and one adjacent side length you rearrange the formula as so:


Then plug in the values:
