finding the equation of a circle??

Question

Points A(2,3) B(-2,5) C(4,-1) all lie on circle O with center (h,k). Find the equation of circle O.

Answer 1

(2 - h)² + (3 - k)² = r²

(-2 - h)² + (5 - k)² = r²

(4 - h)² + (-1 - k)² = r²

 

Use any two to solve for (h, k) then substitute to determine r.