var pantalla = document.querySelector("canvas"); //recibira al canvas de html
var pincel = pantalla.getContext("2d");
pincel.fillStyle = "green";
pincel.fillRect(0, 0, 600, 400);
pincel.fillStyle = "black";
pincel.fillRect(49, 70, 90, 90);
pincel.fillStyle = "black";
pincel.fillRect(205, 70, 90, 90);
pincel.fillStyle = "black";
pincel.fillRect(137, 160, 69, 100);
pincel.fillStyle = "black";
pincel.fillRect(102, 200, 40, 110);
pincel.fillStyle = "black";
pincel.fillRect(204, 200, 40, 110);
