<canvas width="600" height="400">
</canvas>
<script>
var pantalla = document.querySelector("canvas");
var pincel = pantalla.getContext("2d");
pincel.fillStyle = "darkgreen";
pincel.fillRect(200,0,350,300);
pincel.fillStyle = "black";
pincel.fillRect(250,60,90,90);
pincel.fillStyle = "black";
pincel.fillRect(410,60,90,90);
pincel.fillStyle = "black";
pincel.fillRect(340,150,70,100);
pincel.fillStyle = "black";
pincel.fillRect(300,190,40,110);
pincel.fillStyle = "black";
pincel.fillRect(410,190,40,110);
</script>
