TRIANGLE PROBLEM

Question

Hi everyone - I am developing various proofs of the pythagora's theorem
and the following code draws a triangle on screen and the proof follows -
but i need to know how to drag the triangle such tht 1 angle is always set to 90 degrees.
i.e. i need to resize the triangle by dragging its vertex points by which the1 angle remains at 90 no matter what the size.
The proof has got some graphics code hardcoded in it - i.e. LINES AND POLYGONS have been hardcoded
i need to reconfigure that such that everytime the user increases the size of the triagnle and clicks on next it draws the lines and polygons in the correct area and place
PLEASE HELP
the code is as follows
MAIN CLASS
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.*;
import java.awt.event.*;
import java.text.*;
import javax.swing.*;
public class TestProof {
    TestControl control;          // the controls for the visual proof
    TestView view;          // the drawing area to display proof
    // called upon class creation
    public TestProof() {
        view = new TestView();
view.setBackground(Color.WHITE);
        control = new TestControl(view);
        Frame f = new Frame("Pythagoras");
        f.add(view,"Center");
        f.add(control,"South");
        f.setSize(600,600);
        f.setBackground(Color.lightGray);
        f.addMouseMotionListener(
        new MouseMotionListener() { //anonymous inner class
            //handle mouse drag event
            public void mouseMoved(MouseEvent e) {
                System.out.println("Mouse  " + e.getX() +","  + e.getY());
            public void mouseDragged(MouseEvent e) {
                System.out.println("Draggg: x=" + e.getX() + "; y=" + e.getY());
        JMenu File = new JMenu("File");
        JMenuItem Exit = new JMenuItem("Exit");
        Exit.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                ExitActionPerformed(evt);
        JMenuBar menuBar = new JMenuBar();
        menuBar.add(File);
   File.add(Exit);
        f.add(menuBar,"North");
        f.show();
    private JMenuBar getMenuBar() {
        JMenu File = new JMenu("File");
        JMenuItem Exit = new JMenuItem("Exit");
        Exit.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                ExitActionPerformed(evt);
        JMenuBar menuBar = new JMenuBar();
        menuBar.add(File);
             File.add(Exit);   
        return menuBar;
    private void ExitActionPerformed(java.awt.event.ActionEvent evt) {
        // TODO add your handling code here:
        System.exit(0);
    // for standalone use
    public static void main(String args[]) {
  TestProof TP = new TestProof();
}Test VIEW
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.text.*;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class TestView extends Canvas {
    int TRANSLUCENT = 1;
    int sequence;          // sequencer that determines what should be drawn
    // notes matter
    int noteX = 100;     // note coordinates
    int noteY = 60;
    int fontSize = 11;     // font size
    int lineSpacing     // space between two consecutive lines
    = fontSize + 2;
    Font noteFaceFont;     // font used to display notes
    // objects matter
    Polygon tri;          // right-angled triangle with sides A, B, and C
    Polygon tri1;
    Polygon sqrA;          // square with side of length A
    Polygon sqrB;          // square with side of length B
    Polygon sqrC;          // square with side of length C
    Polygon parA;          // parallelogram of base A and height A
    Polygon parB;          // parallelogram of base B and height B
    Polygon poly1;
    Polygon poly2;
    Polygon poly3;
    Polygon poly4;
    Polygon poly5;
    Polygon poly6;
    int X0 = 350;          // coordinates of triangle
    int Y0 = 350;
    int A = 90;//60;          // triangle size
    int B = 120;//80;
    int C = 150;//100;
    //CORDS of 2nd triangle
    int X1 = 350;
    int Y1 = 500;
    // notes: three lines per note
    String notes[] = {
        // note 0
        // note 1
        // note 2
        // note 3
        // note 4
        // note 5
        // note 6
        // note 7
        // note 8
        // note 9
        // note 10
        // note 11
        // note 12
        // note 13
        // note 14
    // constructor
    public TestView() {
        addMouseMotionListener(
        new MouseMotionListener() { //anonymous inner class
            //handle mouse drag event
            public void mouseMoved(MouseEvent e) {
                System.out.println("Mouse  " + e.getX() +","  + e.getY());
            public void mouseDragged(MouseEvent e) {
                System.out.println("Draggg: x=" + e.getX() + "; y=" + e.getY());
        // set font
        noteFaceFont = new Font("TimesRoman", Font.PLAIN, fontSize);
        // (coordinates specified w.r.t. to P0, unless otherwise specified)
        // create the triangle
        tri = new Polygon();
        tri.addPoint(0, 0);                    // add P0 coordinate
        tri.addPoint(A*A/C, -A*B/C);          // add A3 coordinate
        tri.addPoint(C, 0);                    // add C1 coordinate
        tri.translate(X0, Y0);               // place triangle
        tri1 = new Polygon();
        tri1.addPoint(0,0);                    // add P0 coordinate
        tri1.addPoint(A*A/C +38, +A*B/C);          // add A3 coordinate
        tri1.addPoint(C, 0);                    // add C1 coordinate
        tri1.translate(X1, Y1);
        // create square of side A
        sqrA = new Polygon();
        sqrA.addPoint(0, 0);               // add P0 coordinate
        sqrA.addPoint(-A*B/C, -A*A/C);          // add A1 coordinate
        sqrA.addPoint(-A*(B-A)/C, -A*(A+B)/C);     // add A2 coordinate
        sqrA.addPoint(A*A/C, -A*B/C);          // add A3 coordinate
        sqrA.translate(X0, Y0);               // place square
        // create square of side B
        // warning: the coordinate of this object are specified relative to C1
        sqrB = new Polygon();
        sqrB.addPoint(0, 0);               // add C1 coordinate
        sqrB.addPoint(B*A/C, -B*B/C);          // add B1 coordinate
        sqrB.addPoint(B*(A-B)/C, -B*(A+B)/C);     // add B2 coordinate
        sqrB.addPoint(-B*B/C, -B*A/C);          // add A3 coordinate
        sqrB.translate(X0 + C, Y0);               // place square
        // create square of side C
        sqrC = new Polygon();
        sqrC.addPoint(0, 0);               // add P0 coordinate
        sqrC.addPoint(C, 0);               // add C1 coordinate
        sqrC.addPoint(C, C);               // add C2 coordinate
        sqrC.addPoint(0, C);               // add C3 coordinate
        sqrC.translate(X0, Y0);               // place square
        poly1 = new Polygon();
        poly1.addPoint(405,279);
        poly1.addPoint(413,350);
        poly1.addPoint(432,500);
        poly1.addPoint(442,571);
        poly1.addPoint(500,500);
        poly1.addPoint(500,350);
        poly2 = new Polygon();
        poly2.addPoint(279,297);
        poly2.addPoint(404,280);
        poly2.addPoint(571,254);
        poly2.addPoint(500,350);
        poly2.addPoint(350,350);
        //Polygon 3
        poly3 = new Polygon();
        poly3.addPoint(404,280);
        poly3.addPoint(350,350);
        poly3.addPoint(414,350);
        poly4 = new Polygon();
        poly4.addPoint(350,350);
        poly4.addPoint(350,500);
        poly4.addPoint(442,572);
        poly4.addPoint(433,500);
        poly4.addPoint(414,350);
        poly5 = new Polygon();
        poly5.addPoint(476,183);
        poly5.addPoint(332,225);
        poly5.addPoint(278,295);
        poly5.addPoint(404,279);
        poly5.addPoint(571,254);
        poly6= new Polygon();
        poly6.addPoint(405,278);
        poly6.addPoint(332,224);
        poly6.addPoint(476,182);
        // create parallelogram of height A
        parA = new Polygon();
        parA.addPoint(0, 0);               // add P0 coordinate
        parA.addPoint(0, C);               // add C3 coordinate
        parA.addPoint(A*A/C, C - A*B/C);          // add Q0 coordinate
        parA.addPoint(A*A/C, -A*B/C);          // add A3 coordinate
        parA.translate(X0,Y0);               // place parallelogram
        // create parallelogram of height B
        // warning: the coordinate of this object are specified from C1
        parB = new Polygon();
        parB.addPoint(0, 0);               // add C1 coordinate
        parB.addPoint(-B*B/C, -B*A/C);          // add A3 coordinate
        parB.addPoint(A*A/C - C, C - A*B/C);     // add Q0 coordinate
        parB.addPoint(0, C);               // add C2 coordinate
        parB.translate(X0 + C, Y0);
        // place parallelogram
    // depending on the sequence number we draw certain objects
    public void paint(Graphics gfx) {
        super.paint(gfx);
        Graphics2D g = (Graphics2D) gfx;
        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
        RenderingHints.VALUE_ANTIALIAS_ON);
        // text first, then objects (and animation)
        // we always output some notes
        g.drawString(notes[3*sequence], noteX, noteY);
        g.drawString(notes[3*sequence + 1], noteX, noteY + lineSpacing);
        g.drawString(notes[3*sequence + 2], noteX, noteY + 2*lineSpacing);
        // the object are drawn in an order so that they are properly overlapped
        if(sequence == 13) {
            g.setColor(Color.green);
            g.fillPolygon(poly1);
            g.fillPolygon(poly2);
            g.fillPolygon(poly3);
            g.fillPolygon(poly4);
            g.fillPolygon(poly5);
            g.setColor(Color.RED);
            g.setColor(Color.GREEN);
            g.drawLine(413,351,433,499);
            g.setColor(Color.white);
            g.fillPolygon(tri);
            g.fillPolygon(tri1);
            g.fillPolygon(poly6);
        if(sequence == 12 ) {
            g.setColor(Color.green);
            g.fillPolygon(poly1);
            g.fillPolygon(poly2);
            g.fillPolygon(poly3);
            g.fillPolygon(poly4);
            g.fillPolygon(poly5);
            g.setColor(Color.BLACK);
        if(sequence == 11){
            g.setColor(Color.green);
            g.fillPolygon(poly1);
            g.fillPolygon(poly3);
            g.fillPolygon(poly4);
            g.setColor(Color.BLACK);
        if(sequence == 8 ){
            g.setColor(Color.green);
            g.fillPolygon(poly5);
            g.setColor(Color.MAGENTA);
            g.drawString("E",578,254);
            g.drawString("D",268,302);
            g.setColor(Color.black);
            g.drawArc(250,150,350,250,320,65);
        else if (sequence == 9 ){
            g.setColor(Color.green);
            g.fillPolygon(poly2);
            g.setColor(Color.MAGENTA);
            g.drawString("E",578,254);
            g.drawString("D",268,302);
            g.setColor(Color.black);
            g.drawArc(250,150,350,250,320,65);
        if( sequence == 10){
            g.setColor(Color.green);
            g.fillPolygon(poly2);
            g.fillPolygon(poly5);
            g.setColor(Color.black);
            g.setColor(Color.MAGENTA);
            g.drawString("E",578,254);
            g.drawString("D",268,302);
            g.setColor(Color.black);
            g.drawArc(250,150,350,250,320,65);
        if(sequence == 7){
            g.setColor(Color.green);
            g.fillPolygon(poly2);
            g.setColor(Color.MAGENTA);
            g.drawString("E",578,254);
            g.drawString("D",268,302);
            g.setColor(Color.black);
        if(sequence == 6){
            g.setColor(Color.yellow);
            g.fillPolygon(poly2);
            g.setColor(Color.green);
            g.fillPolygon(poly3);
            g.setColor(Color.blue);
            g.fillPolygon(poly4);
            g.setColor(Color.black);
            g.drawArc(250,175,350,275,300,65);
            //g.drawArc(250,150,350,250,320,65);
            g.drawLine( 606,309,599,299);
            g.drawLine(592,313, 599,299);
            g.drawString("+90 degrees",605,378);
        if (sequence == 5 ) {
            g.setColor(Color.yellow);
            g.fillPolygon(poly2);
            g.setColor(Color.black);
        if (sequence == 4) {
            g.setColor(Color.YELLOW);
            g.fillPolygon(poly1);
            g.setColor(Color.black);
            g.drawArc(319,310,250,195,89,-35);
            g.drawLine(499,319, 492,312);
            g.drawLine(499,319, 492,325);
            g.drawArc(200,180, 233,238,-120,-60);
            g.drawLine(200,298, 208,309);
            g.drawLine(200,298, 194,313);
            g.drawString("-90 degrees",227,347);
        if (sequence >= 3) {
            g.drawLine(404,279,442,572);
        // draw the squares
        if (sequence >= 2) {
            g.drawLine(278,296,572,254);
        // draw the squares
        if (sequence >= 1) {
            g.drawLine(333,224,476,182);
            g.drawPolygon(tri1);
        // always draw the triangle
        g.drawPolygon(tri);
        g.drawPolygon(sqrA);
        g.drawPolygon(sqrB);
        g.drawPolygon(sqrC);
        g.setColor(Color.MAGENTA);
        g.drawString("C", X0 + C/2 - fontSize/2, Y0 + lineSpacing);
        g.drawString("A",
        X0 + A*A/(2*C) - fontSize*A/B/2,
        Y0 - A*B/(2*C) - lineSpacing*A/B);
        g.drawString("B",
        X0 + C - B*B/(2*C) - fontSize*A/B/2,// the last "-" isn't log.
        Y0 - B*A/(2*C) - lineSpacing*A/B);
    public void redraw(int sequence) {
        this.sequence = sequence;
        repaint();
}TEST CONTROL
* TestControl.java
* Created on 28 February 2005, 11:16
import java.awt.*;
import java.awt.event.*;
import java.text.*;
import javax.swing.JFrame;
* @author  Kripa Bhojwani
public class TestControl extends Panel implements ActionListener {
  TestView view;
  int sequence;                    // event sequence
  // constructor
  public TestControl(TestView view) {
    Button b = null;
    Label label = new Label("A^2 ");
    this.view = view;          // initialize drawble area
    sequence = 0;               // initialize sequence
    b = new Button("Prev");
    b.addActionListener(this);
    add(b);
    b = new Button("Next");
    b.addActionListener(this);
    add(b);
    add(label);
  // exported method
  public void actionPerformed(ActionEvent ev) {
    String label = ev.getActionCommand();
    if (label.equals("Prev")) {
      if (sequence >0) {
     --sequence;
    else {
      if (sequence < 15) {
     ++sequence;
    this.setEnabled(false);          // disable the controls
    view.redraw(sequence);
    this.setEnabled(true);          // enable the controls
}Please help --- really need to sort this out...
THANKS

Answer 1

Cross post http://forum.java.sun.com/thread.jspa?threadID=603432&messageID=3251958#3251958