Grafica en netbeans

package finalgrafica;

import java.awt.Color;
import java.awt.Graphics;

public class FinalgraficaFrame extends javax.swing.JFrame {

public FinalgraficaFrame() {initComponents();
}

@SuppressWarnings("unchecked")
// //GEN-BEGIN:initComponents
private void initComponents() {

Pane = new javax.swing.JPanel();
btnDibujar = newjavax.swing.JButton();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

Pane.setBorder(new javax.swing.border.MatteBorder(null));

javax.swing.GroupLayoutPaneLayout = new javax.swing.GroupLayout(Pane);
Pane.setLayout(PaneLayout);
PaneLayout.setHorizontalGroup(PaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 322, Short.MAX_VALUE)
);
PaneLayout.setVerticalGroup(
PaneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGap(0, 240, Short.MAX_VALUE)
);

btnDibujar.setText("Dibujar");
btnDibujar.addActionListener(new java.awt.event.ActionListener() {
public voidactionPerformed(java.awt.event.ActionEvent evt) {
btnDibujarActionPerformed(evt);
}
});

javax.swing.GroupLayout layout = newjavax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGroup(layout.createSequentialGroup()
.addGap(155, 155, 155)
.addComponent(btnDibujar)
.addContainerGap(178, Short.MAX_VALUE)).addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(66, Short.MAX_VALUE)
.addComponent(Pane, javax.swing.GroupLayout.PREFERRED_SIZE,...