((x2^2 - 2*x2*x3 + x3^2 + y2^2 - 2*y2*y3 + y3^2)*
       (x1^4 - 2*x1^3*x2 + x1^2*x2^2 - 2*x1^3*x3 + 4*x1^2*x2*x3 -
          2*x1*x2^2*x3 + x1^2*x3^2 - 2*x1*x2*x3^2 + x2^2*x3^2 +
    2*x1^2*y1^2 -
          2*x1*x2*y1^2 + x2^2*y1^2 - 2*x1*x3*y1^2 + x3^2*y1^2 + y1^4 -
          2*x1^2*y1*y2 + 4*x1*x3*y1*y2 - 2*x3^2*y1*y2 - 2*y1^3*y2 +
    x1^2*y2^2 -
          2*x1*x3*y2^2 + x3^2*y2^2 + y1^2*y2^2 - 2*x1^2*y1*y3 +
    4*x1*x2*y1*y3 -
          2*x2^2*y1*y3 - 2*y1^3*y3 + 4*y1^2*y2*y3 - 2*y1*y2^2*y3 +
    x1^2*y3^2 -
          2*x1*x2*y3^2 + x2^2*y3^2 + y1^2*y3^2 - 2*y1*y2*y3^2 +
    y2^2*y3^2))

(x1^2 - 2*x1*x2 + x2^2 + (y1 - y2)^2)*(x1^2 - 2*x1*x3 + x3^2 + (y1 - y3)^2)*
 (x2^2 - 2*x2*x3 + x3^2 + (y2 - y3)^2)