<canvas width="600" height="400"></canvas>
<script>
// document.write("<h1>Hola</h1>");
var pantalla = document.querySelector("canvas");
var pincel = pantalla.getContext("2d");
pincel.fillStyle = "lightgrey"
pincel.fillRect(0,0,600,400);
pincel.fillStyle = "green"
pincel.fillRect(0,0,200,400);
pincel.fillStyle = "red"
pincel.fillRect(400,0,200,400);
</script>
