Canvas:-Creating a rectangle, line and circle in Canvas

creating a rectangle , line and circle in Canvas is not coming in HTML practice.
Please check following codes and suggest where is mistake.

Your browser doesn't support Canvas tag
<script>
	var c =document.getElementById("mycircle");
	var ctx c.getContext("2d");
	ctx.beginpath();
	ctx.arc(95,50,40,0,2*Math pi);
	ctx.stroke ();
</script>
var c =document.getElementById("mycircle");

var ctx = c.getContext("2d");

ctx.beginpath();

ctx.arc(95,50,40,0,2*Math.PI);

ctx.stroke ();