Работа с геометрическими фигурами

class figure
{
 protected:
   int xF,yF; //Координаты
   int len;  //Длина
   int width;   //Ширина
   int height;  //Высота
 public:
   //конструктор
   figure(int x, int y, int l, int w, int h):
   xF(x), yF(y), len(l), width(w), height(h)
   {}
//Прототипы методов класса
void draw_rect();
void draw_trap();
void draw_paral();
void movement(float fi);
};
 
 
//--------------Прямоугольник------------------
void figure::draw_rect()
{
  TPoint tPoints[4];
  tPoints[0] = TPoint(xF, yF);
  tPoints[1] = TPoint(xF + len, yF);
  tPoints[2] = TPoint(xF + len, yF + width);
  tPoints[3] = TPoint(xF, yF + width);
  tPoints[4] = TPoint(xF, yF);
  Form1->Canvas->Polygon(tPoints,4);
}
 
//--------------Трапеция----------------------
void figure::draw_trap()
{
  TPoint tPoints[4];
  tPoints[0] = TPoint(xF, yF);
  tPoints[1] = TPoint(xF + len, yF);
  tPoints[2] = TPoint(xF + width, yF + height);
  tPoints[3] = TPoint(xF, yF + height);
  tPoints[4] = TPoint(xF, yF);
  Form1->Canvas->Polygon(tPoints,4);
}
 
//--------------Параллелограмм----------------------
void figure::draw_paral()
{
  TPoint tPoints[4];
  tPoints[0] = TPoint(xF, yF);
  tPoints[1] = TPoint(xF + len, yF);
  tPoints[2] = TPoint(xF + len + sqrt(width*width-height*height), yF + height);
  tPoints[3] = TPoint(xF + sqrt(width*width-height*height), yF + height);
  tPoints[4] = TPoint(xF, yF);
  Form1->Canvas->Polygon(tPoints,4);
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::Button1Click(TObject *Sender)
{
  Form1->Canvas->Pen->Color=clBlack;
  if (Form1->ColorDialog1->Execute())
  {Form1->Canvas->Brush->Color = Form1->ColorDialog1->Color;}
  int len = StrToInt(Form1->Edit1->Text);
  int width = StrToInt(Form1->Edit2->Text);
  int height = StrToInt(Form1->Edit3->Text);
  int X = Form1->Width/2;
  int Y = Form1->Height/2;
  figure f(X,Y,len,width,height);
  switch (Form1->ComboBox1->ItemIndex)
  {
   case 0:
     f.draw_rect();break;
   case 1:
     f.draw_trap();break;
   case 2:
     f.draw_paral();break;
  }
}