Java by API/java.awt/Rectangle

Rectangle: grow(int h, int v)

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MainClass extends JPanel {
  public void paint(Graphics g) {
    Graphics2D g2 = (Graphics2D) g;
    
    Rectangle r = new Rectangle (100, 100, 200, 200);
    r.grow (-25, -50);
    g2.fill (r);
    System.out.println (r);
    
    
  }
  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);
  }
}

Rectangle: intersection(Rectangle r)

import java.awt.Graphics;
import java.awt.Rectangle;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MainClass extends JPanel {
  public void paint(Graphics g) {
    Rectangle r = new Rectangle(50, 50, 100, 100);
    Rectangle r1 = new Rectangle(100, 100, 75, 75);
    g.drawRect(r.x, r.y, r.width, r.height);
    g.drawRect(r1.x, r1.y, r1.width, r1.height);
    Rectangle r2 = r.intersection(r1);
    System.out.println(r2);
    g.fillRect(r2.x, r2.y, r2.width, r2.height);
  }
  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);
  }
}