Java tutorial
/* * Output: * */ import java.awt.Graphics; import javax.swing.JFrame; import javax.swing.JPanel; public class MainClass extends JPanel { public void paint(Graphics g) { int xpoints[] = { 25, 145, 25, 145, 25 }; int ypoints[] = { 25, 25, 145, 145, 25 }; int npoints = 5; g.drawPolygon(xpoints, ypoints, npoints); } public static void main(String[] args) { JFrame frame = new JFrame(); frame.getContentPane().add(new MainClass()); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(200, 200); frame.setVisible(true); } }