Rectangle brush on paint instead of circle

1

I have a paint brush that has a stroke of a circle i wanted to replaced it with rectangle instead here is my code.

	private function drawCircle():Void
	{
		var r:Number = 40;
		var xcenter:Number = _xmouse;
		var ycenter:Number = _ymouse;
		var A:Number = Math.tan(22.5*Math.PI/180);
		var endx:Number;
		var endy:Number;
		var cx:Number;
		var cy:Number;
		var xend:Number;
		var yend:Number;
		var xbegin: Number;
		var ybegin: Number;

		emptyMask.beginFill(0x000000,100);
		emptyMask.moveTo(xcenter+r,ycenter);
		for (var angle:Number = Math.PI/4; angle<=2*Math.PI; angle += Math.PI/4) {
			xend = r*Math.cos(angle);
			yend = r*Math.sin(angle);

			xbegin = xend+r*A*Math.cos((angle-Math.PI/2));
			ybegin = yend+r*A*Math.sin((angle-Math.PI/2));
			emptyMask.curveTo(xbegin+xcenter,ybegin+ycenter,xend+xcenter,yend+ycenter);
		}
		emptyMask.endFill();
	}