<html>
<body>
  <canvas width="500" height="500"></canvas>
<script>
  var canvas = document.getElementsByTagName('canvas')[0];
  var ctx = canvas.getContext('2d');
  ctx.scale(0.5, 0.5);

  ctx.translate(41, 41.);
  ctx.rect(0, 0, 100, 100);
  ctx.moveTo(100,0);
  ctx.quadraticCurveTo(200, 100, 300,0);
  ctx.moveTo(300,0);
  ctx.bezierCurveTo(400, 100, 500, -100, 600,0);

  ctx.stroke();
</script>
</body>
</html>