HTML canvas example
Example 1: javascript canvas
<canvas id="canvas"></canvas>
<script>
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
ctx.beginPath();
ctx.rect(x, y, width, height);
ctx.fillStyle = 'limegreen';
ctx.fill();
ctx.beginPath();
ctx.arc(x, y, radius, startAngle, endAngle, counterClockWise(optional));
ctx.strokeStyle = 'black';
ctx.stroke();
</script>
Example 2: javascript create canvas
var canvas = document.createElement("canvas"); //Create canvas
document.body.appendChild(canvas); //Add it as a child of <body>
Example 3: html5 canvas
<canvas id="" width="" height=""></canvas>
<script>
</script>