Programa de java

import java.awt.*;

import java.applet.*;

public class appareatri extends Applet {

        TextField txtbase,txtaltura,txtarea;

        Button btncalcular,btnlimpiar;

        double base,altura,area;

        public void init() {

                txtbase=new TextField(15);

                txtaltura=new TextField(15);

                txtarea=new TextField(15);

                btncalcular=new Button("calcular");

                btnlimpiar=new Button("limpiar");

                txtarea.setEditable(false);

                setLayout(null);

                txtbase.setBounds(170 ,95 ,120 ,20);

                txtaltura.setBounds(170 ,145 ,120 ,20);

                txtarea.setBounds(170 ,195 ,120 ,20);

                btncalcular.setBounds(340 ,195 ,120 ,20);

                btnlimpiar.setBounds(340 ,245 ,120 ,20);

                        add(txtbase);add(txtaltura);add(txtarea);

                add(btncalcular);add(btnlimpiar);

        }

        public void paint(Graphics g) {

                g.setColor(Color.red);

                g.drawString("AREA DEL TRIANGULO", 50, 50 );

                g.setColor(Color.blue);

                g.drawString("Base en cm: ", 50,110);

                g.drawString("Altura en cm: ", 50,160);

                g.setColor(Color.black);

                g.drawString("Area en cm2: ",50,210);

        }

        public boolean action(Event e, Object o) {

                if(e.target==btncalcular) {

                        altura=Double.parseDouble(txtaltura.getText());

                        base=Double.parseDouble(txtbase.getText());

                        area=(base*altura)/2;

                        txtarea.setText(String.valueOf(area));

                }  

                if(e.target==btnlimpiar){

                        txtaltura.setText("");

                        txtbase.setText("");

                        txtarea.setText("");

                }

                                return true;            

        }

}

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