​x
 
<!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.beginPath();
ctx.arc(100,75,50,0,2*Math.PI);
ctx.stroke();
​
</script> 
​
</body>
</html>
​