Untitled

<!DOCTYPE html>
<html>
<body>


<p id="demo"></p>

 <canvas id="myCanvas" width="200" height="100" style="border:1px solid #000000;">
</canvas>

<script>

var number = 10;

var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.beginPath();
ctx.arc(95,50,number,0,2*Math.PI);
ctx.stroke();


document.addEventListener("keyup", function(){
    document.getElementById("demo").innerHTML = "Hello World!";
    number++;

ctx.arc(95,50,number,0,2*Math.PI);
ctx.stroke();
});


</script>

</body>
</html>