Three Points on a circle: (-17,-2), (0,15), (9,-2). What is the equation of the circle?
Because the circumcenter is the intersection of perpendicular bisectors, we can graph two perpendicular bisectors from two lines. Then we know the circle's center, (-4,2). Once we get the radius, we can use the formula (x-a)^2+(y-b)^2=r^2 where a and b are the coordinates of the circles center.