nterX;
        this.y = centerY;
        this.radius = radius;
        this.sides = sides;
        this.startAngle = startAngle;
        this.strokeStyle = strokeStyle;
        this.fillStyle = fillStyle;
        this.filled = filled;
    };

    Polygon.prototype = {
        getPoints: function () {
            var points = [],
                angle = this.startAngle || 0;

            for (var i=0; i < this.sides; ++i) {
                points.push(new Point(this.x + this.radius * Math.sin(angle),
       