Need help

import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
import java.awt.Color;
public class Label extends Actor
{
    
    
    public Label()
    {
       GreenfootImage img = new GreenfootImage(600,400);
        img.setColor(Color.WHITE);
        img.fill();
        img.setColor(Color.BLACK);
        img.drawString("Dreieck animation",300,200);
           
      
        setImage(img);
         
        }
    public void Act()
        {
            
        drawD();
         
        
            }
    public void drawD()
        {
        GreenfootImage img = getImage();
          int q= Greenfoot.getRandomNumber(255);
          int w= Greenfoot.getRandomNumber(255);
          int e= Greenfoot.getRandomNumber(255);
          img.setTransparency(255);
          int[] a= {Greenfoot.getRandomNumber(600),Greenfoot.getRandomNumber(600),Greenfoot.getRandomNumber(600)};
          int[] b= {Greenfoot.getRandomNumber(400),Greenfoot.getRandomNumber(400),Greenfoot.getRandomNumber(400)};
          img.setColor(new Color(q,w,e));
          img.fillPolygon(a,b,3);
          img.setColor(new Color(0,0,0));
          img.drawPolygon(a,b,3);
          setImage(img);
        
        }
       }