Java Applet ile yapılmış üçgen çizen program

package applet;

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;



public class ucgen extends Applet implements Runnable{
  
     private int x;
    int y;
    int z; 
    int t;
                int c=600;

    int h=600;
    public void init(){
        
        setSize(600,600);
        
        Thread g=new Thread(this);
        
        g.start();
        
       
    }
    public void paint(Graphics a){
      
        setBackground(Color.black);
        a.setColor(Color.yellow);
     
      a.drawLine(300, 0, x, y);
      a.drawLine(0,600, z, 600);
      a.drawLine(600, 600, h, c);      //TEK DRAWLINE ILE UCGEN YAPILIRMI?
    }
    
    public void run(){
        try{
       
            for (int i = 0; i < 1; i++) {
                
            
 
            for (x = 300;  x>0; x--) {
                Thread.sleep(10);
                y+=2;
                repaint();
                
            }
             for (z = 0; z < 600; z++) {
               
                Thread.sleep(10);
                repaint();
            }
    for (h = 600;  h> 300; h--) {
                    Thread.sleep(10);
                    c-=2;
                    repaint();
                }
                
                
               
            }
        }catch(Exception f){
            
        }
    }
    
}

Ekran Görüntüsü;