Step 1: Recall the standard form of the circle

          NOTE: A circle is the set of points in a plane that are the same distance

            from a fixed point. The distance is the radius. The point is the center.

       The equation of a circle in standard form is  (x - h)^2 + (y - k)^2 = r^2 The center is (h,k). The radius is r.

Step 2: Convert  the given equation into the standard form

            NOTE: Make sure the terms with  x^2 and y^2 are on

                        the left side of the equation and the constant is on the right.

            EXAMPLE: x^2 + y^2 - 36 = 0   

                                x^2 + y^2 = 36