<canvas width = "600" height = "400"> </canvas>
<script>
var pantalla = document.querySelector("canvas");
var pincel = pantalla.getContext("2d");
pincel.fillStyle = "darkgreen" // Propiedad
pincel.fillRect(0,0,350,300); // Funcion
pincel.fillStyle = "black"
pincel.fillRect(50,50,90,90);
pincel.fillStyle = "black"
pincel.fillRect(200,50,90,90);
pincel.fillStyle = "black"
pincel.fillRect(138,140,65,100);
pincel.fillStyle = "black"
pincel.fillRect(90,185,50,115);
pincel.fillStyle = "black"
pincel.fillRect(200,185,50,115);
</script>