Java program for side of a square

import java.util.*;

public class Sideofsquare
{
 public static void main(String[] args)
  {Scanner kbd = new Scanner(System.in);
   System.out.print("Enter Co-ordinates of first vertex: ");
   double x1 = kbd.nextDouble();
   double y1 = kbd.nextDouble();
   System.out.print("Enter Co-ordinates of second vertex: ");
   double x2 = kbd.nextDouble();
   double y2 = kbd.nextDouble();
   System.out.print("Enter Co-ordinates of third vertex: ");
   double x3 = kbd.nextDouble();
   double y3 = kbd.nextDouble();
   double a = Math.sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
   double b = Math.sqrt((x1-x3)*(x1-x3)+(y1-y3)*(y1-y3));
   double c = Math.sqrt((x3-x2)*(x3-x2)+(y3-y2)*(y3-y2));
   double s = (a+b+c)/2;
   double area = Math.sqrt(s*(s-a)*(s-b)*(s-c));
   double sarea = area;
   System.out.println("Side of square = " + Math.sqrt(sarea));
  }
}