how to make a block in a canvas html code 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: javascritp canvas

//Creates a canvas and draws a circle
var canvas = document.body.appendChild(document.createElement("canvas"));
var ctx = canvas.getContext("2d");

ctx.beginPath();
ctx.arc(canvas.width / 2, canvas.height / 2, 50, 0, Math.PI * 2);
ctx.fillStyle = "red";
ctx.strokeStyle = "black";
ctx.stroke();
ctx.fill();