Area.java

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

class Area extends JFrame implements ActionListener {
 JButton clear, circle, rectangle, triangle;
 JTextField radius, length, breadth, len, bread, height, result;
 JLabel l, b, h, r, l1, b1, heading, res;

 Area() {
 super("Area Application");
 this.clear = new JButton("CLEAR");
 this.circle = new JButton("CIRCLE");
 this.rectangle = new JButton("RECTANGLE");
 this.triangle = new JButton("TRIANGLE");

 this.l = new JLabel("LENGTH");
 this.b = new JLabel("BREADTH");
 this.h = new JLabel("HEIGHT");
 this.r = new JLabel("RADIUS");
 this.l1 = new JLabel("LENGTH-TRIANGLE");
 this.b1 = new JLabel("BREADTH-TRIANGLE");
 this.heading = new JLabel("Area Calculator");
 this.res = new JLabel("RESULT");

 this.radius = new JTextField(10);
 this.length = new JTextField(10);
 this.breadth = new JTextField(10);
 this.len = new JTextField(10);
 this.bread = new JTextField(10);
 this.height = new JTextField(10);
 this.result = new JTextField(10);

 this.add(this.clear);
 this.add(this.circle);
 this.add(this.rectangle);
 this.add(this.triangle);

 this.add(this.l);
 this.add(this.b);
 this.add(this.h);
 this.add(this.r);
 this.add(this.l1);
 this.add(this.b1);
 this.add(this.heading);
 this.add(this.res);

 this.add(this.radius);
 this.add(this.length);
 this.add(this.breadth);
 this.add(this.len);
 this.add(this.bread);
 this.add(this.height);
 this.add(this.result);
 this.setLayout(null);

 this.heading.setBounds(20, 10, 150, 20);
 this.l.setBounds(20, 30, 150, 20);
 this.length.setBounds(20, 50, 150, 20);
 this.b.setBounds(20, 70, 150, 20);
 this.breadth.setBounds(20, 90, 150, 20);
 this.r.setBounds(20, 110, 150, 20);
 this.radius.setBounds(20, 130, 150, 20);
 this.l1.setBounds(20, 150, 150, 20);
 this.len.setBounds(20, 170, 150, 20);
 this.b1.setBounds(20, 190, 150, 20);
 this.bread.setBounds(20, 210, 150, 20);
 this.h.setBounds(20, 230, 150, 20);
 this.height.setBounds(20, 250, 150, 20);
 this.res.setBounds(20, 270, 150, 20);
 this.result.setBounds(20, 290, 150, 20);

 this.clear.setBounds(200, 150, 150, 100);
 this.circle.setBounds(350, 150, 150, 100);
 this.rectangle.setBounds(500, 150, 150, 100);
 this.triangle.setBounds(650, 150, 150, 100);

 this.setVisible(true);
 this.setDefaultCloseOperation(EXIT_ON_CLOSE);
 this.setSize(500, 300);

 this.clear.addActionListener(this);
 this.circle.addActionListener(this);
 this.rectangle.addActionListener(this);
 this.triangle.addActionListener(this);
 }

 public void actionPerformed(ActionEvent ae) {
 Object source = ae.getSource();
 double len1, bread1, area1, h1, rad;
 int len2, bread2, area;
 try {
 if (source == this.circle) {
 rad = Double.parseDouble(this.radius.getText());
 area1 = 3.14 * rad * rad;
 this.result.setText(Double.toString(area1));
 } else if (source == this.rectangle) {
 len2 = Integer.parseInt(this.length.getText());
 bread2 = Integer.parseInt(this.breadth.getText());
 area = len2 * bread2;
 this.result.setText(Integer.toString(area));
 } else if (source == this.triangle) {
 bread1 = Double.parseDouble(this.bread.getText());
 h1 = Double.parseDouble(this.height.getText());
 area1 = 0.5 * bread1 * h1;
 this.result.setText(Double.toString(area1));
 } else if (source == this.clear) {
 this.radius.setText("");
 this.result.setText("");
 this.len.setText("");
 this.bread.setText("");
 this.length.setText("");
 this.breadth.setText("");
 this.height.setText("");
 }
 } catch (Exception e) {
 this.result.setText("Enter valid values");
 }
 }

 public static void main(String args[]) {
 Area a1 = new Area();
 }
}