<canvas width="600" height="400">
</canvas>
<script>
var pantalla = document.querySelector("canvas");
var pincel = pantalla.getContext("2d");
pincel.fillStyle = "lightgrey";
pincel.fillRect(0,0,600,400);
//1
pincel.fillStyle = "darkgreen";
pincel.fillRect(125,50,350,300);
//2
pincel.fillStyle = "black";
pincel.fillRect(175,110,90,90);
//3
pincel.fillStyle = "black";
pincel.fillRect(335,110,90,90);
//4
pincel.fillStyle = "black";
pincel.fillRect(265,200,70,100);
//5
pincel.fillStyle = "black";
pincel.fillRect(225,240,40,110);
//6
pincel.fillStyle = "black";
pincel.fillRect(335,240,40,110);
</script>