/*
  Distanza fra due punti.
*/

import java.awt.*;

public class Distanza extends java.applet.Applet {
  int xpremuto, ypremuto;

  public boolean mouseDown(Event e, int x, int y) {
    Graphics g=getGraphics();

    g.drawLine(x-10,y,x+10,y);
    g.drawLine(x,y-10,x,y+10);

    xpremuto=x;
    ypremuto=y;

    return true;
  }

  public boolean mouseUp(Event e, int x, int y) {
    Graphics g=getGraphics();
    double d;

    g.clearRect(xpremuto-10,ypremuto-10,21,21);
    g.clearRect(0,0,200,20);

    d=Math.sqrt((double) (x-xpremuto)*(x-xpremuto) + (y-ypremuto)*(y-ypremuto));

    g.drawString(""+d,10,20);

    return true;
  }
}