<canvas width="500" height ="450"> // esto es alto y largo</canvas>
<script>
document.write("<h2>Holi mor</h3>")
var display = document.querySelector("canvas");
var drawPincel = display.getContext("2d"); //este es el pincel
drawPincel.fillStyle = "pink";
drawPincel.fillRect(0,0,500,450);
drawPincel.fillStyle = "black";
drawPincel.beginPath();
drawPincel.moveTo(50,50);
drawPincel.lineTo(50,400);
drawPincel.lineTo(400,400);
drawPincel.moveTo(50,400);
drawPincel.lineTo(400,400);
drawPincel.fill();
drawPincel.fillStyle = "pink";
drawPincel.beginPath();
drawPincel.moveTo(100,175);
drawPincel.lineTo(100,350);
drawPincel.lineTo(275,350);
drawPincel.moveTo(100,350);
drawPincel.lineTo(275,350);
drawPincel.fill();
</script>