Tryit Editor v2.9

Edit This Code:
<!DOCTYPE html>
<html>
<body>

<canvas id="myCanvas" width="300" height="150" style="border:1px solid #d3d3d3;">
Your browser does not support the HTML5 canvas tag.</canvas>

<script>

var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.rect(20, 20, 150, 100);
ctx.stroke();

</script> 

</body>
</html>