If  $\gamma =16\sin \frac{\pi }{9}\sin \frac{2\pi }{9}\sin \frac{3\pi }{9}\sin \frac{4\pi }{9}$ $\alpha =\cos \frac{\pi }{7}+\cos \frac{3\pi }{7}+\cos \frac{5\pi }{7}$  and $\beta =\cos \frac{2\pi }{7}+\cos \frac{4\pi }{7}+\cos \frac{6\pi }{7}$ then the equation the circle whose center at $(2\alpha ,2\beta )$ and $\gamma$   is radius is