An archeologist found the remains of an ancient wheel,which she placed on a grid.If an arc of the wheel passes through A(-9,0),B(-3,4),and C(9,0),locate the center of the wheel,and the standard equation of the circle defining its boundary.
Very similar to this problem, here :
https://web2.0calc.com/questions/coordinates_63#r1
See if you can work this one out, based on that....