In the given problem, the chord of the circle forms right triangles with a perpendicular line that passes through the center of the circle. Therefore, the length of the chord is bisected and we get the following triangles:
We can use the Pythagorean theorem to determine the value of the radius:
Solving the operations:
Now we take the square root to both sides:
Therefore, the radius of the arc is 292.6 ft.