JS Canvas Draw Random 3D Triangle SRC

<html>
<center>
<body bgcolor="lightblue">
<canvas id="canvas" width="500" height="500" style="border:1px;"></canvas>
<script>
  var canvas = document.querySelector('#canvas').getContext('2d'),side = 0,
    size = 100,
    x = 100,
    y = 100;

canvas.beginPath();
canvas.moveTo(Math.random()*x + size * Math.cos(1), y + size * Math.cos(1));

for (side; side < 12+1; side++) {
  canvas.lineTo(x + size * Math.cos(side * 8 * Math.PI / 12), y + size * Math.sin(side * 4 * Math.PI / 12));
}

canvas.strokeStyle = "#000000";
canvas.stroke();
canvas.fillStyle = "#00FF00";
canvas.fill();
</script>
</body>
</center>
</html>