Find the radius of a circle with the given circumference. 15x ft.

circumference of the circle = 15x ft.

or, 2πr = 15x ft.

or, 2*22/7 * r = 15 x ft.

or, r = 15x ft. / 44/7

or, r = 15*7x ft / 44

or, r = 2.387xft

therefore, radius of the circle is 2.387x ft.

Answer: the formula for the circumference of a circle is pi times the diameter. The diameter of a circle is the radius times 2.