import java.awt.*; 
import javax.swing.*; 

public class InvisibleRectangle extends JFrame { 
  public static final long serialVersionUID = 1L; 

  public InvisibleRectangle() { 
    setSize(400, 300); 
    setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); 
    setVisible(true); 
  } 


  public static void main(String args[]) { 
    SwingUtilities.invokeLater(InvisibleRectangle::new); 
  } 


  public void paint(Graphics g) { 
    g.translate(0, 200); 
    g.setColor(Color.BLACK); 
    g.drawLine(50,0, 50, -150); // ordinate 
    g.drawLine(50,0, 300,0); // abscissa 
    g.setColor(Color.BLUE); 
    g.fillRect(100,0, 30,-80); // Above abscissa; does not paint. 
    g.fillRect(150,0, 30,50); // Below abscissa. 
  } 

}