Untitled

<!DOCTYPE HTML>
<html>
    <head>
        <style>
        body {
            margin: 0px;
            padding: 0px;
        }
        </style>
    </head>
    <body>
        <canvas id="myCanvas" width="1200" height="1000"></canvas>
        <script>
            function Point(x, y) {
                this.X = x;
                this.Y = y;
            }
            var canvas = document.getElementById('myCanvas');
            var context = canvas.getContext('2d');
            var alpha = Math.PI * 0.275,
                beta = -Math.PI * 0.35,
                ratioA = 0.775,
                ratioB = 0.45,
                MIN_LENGTH = 5;

            function drawLine(rootPoint, r, theta) {

                context.beginPath();
                var endX = rootPoint.X + r*Math.cos(theta);
                var endY = rootPoint.Y + r*Math.sin(theta);
                var endPoint = new Point(endX, endY);

                context.moveTo(rootPoint.X, rootPoint.Y);
                context.lineTo(endPoint.X, endPoint.Y);
                context.stroke();

                if (r*ratioA < MIN_LENGTH || r*ratioB < MIN_LENGTH) {
                    return;
                }
                drawLine(endPoint, r*ratioA, theta+alpha);
                drawLine(endPoint, r*ratioB, theta+beta);
            }
            var startPoint = new Point(300, 500);
            drawLine(startPoint, 200, Math.PI * 3/2);
        </script>
    </body>
</html>