# Thread: equation of a circle

1. ## equation of a circle

How to solve the equation of a circle, given with three points that passes through the circle?
And if possible, can anyone give me an example?

thnx

2. $(x-u)^2+(y-v)^2=r^2$
Just substitute the given $(x,y)$ pairs into the equation above. You get three equations and need to solve for $u, v, r$.