actionscript 3.0 Rectangle extends sprite

//Rectangle.as
package
{
 import flash.display.Shape;
 public class Rectangle extends Shape
 {
  public function Rectangle(w:Number, h:Number,lineThikness:Number, lineColor:uint, fillColor:uint)
  {
   graphics.lineStyle(lineThikness,lineColor);
   graphics.beginFill(fillColor);
   graphics.drawRect(0,0,w,h);
  }
 }
}


//extendsProject.as
package
{
 import flash.display.Sprite;
 
 public class extendsProject extends Sprite
 {
  public function extendsProject()
  {
   var rect:Rectangle = new Rectangle(100,50,3,0xFF0000,0x0000FF);
   this.addChild(rect);
  }
 }
}