SOLUTION: Find the equation of the circle which passes through points a(0,2), b(2,0) and c(-4,0)

1.  Considering the points A and B, you can conclude that the center lies in the straight line  y = x,  

    which is the angle bisector of the first and the third quadrants right angle.


2.  Considering the points B and C, you can conclude that the center lies in vertical line x = -1.


3.  From n1)  and  n2), it follows that the center is the point (x,y) = (-1,-1).


4.  The radius is   =  = .


5.  Thus the equation of the circle is 

     = 10.