import javax.swing.JPanel;
import javax.swing.JFrame;
import java.awt.*;
public class lines extends JFrame
{
    public  void Lines(Graphics g)
   {
       for (int i=0;i<=20;i++)
       {
           g.setColor(Color.BLUE);
           g.drawLine(15*i,15*i,600-15*i,10*i);
        }
        g.drawLine(0,0,300,200);
        g.drawLine(600,0,300,200);
   }
   public static void main (String [] args) //frame
    {
        lines panel = new lines();
        JFrame application = new JFrame();
        application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        application.setSize(600, 200);
        application.setVisible(true);
    }
}