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var pantalla = document.querySelector("canvas");
var pincel = pantalla.getContext("2d");
pincel.fillStyle = "green"
pincel.fillRect(0,0,600,400);
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pincel.fillRect(45,50,90,90)
pincel.fillStyle = "black"
pincel.fillRect(200,50,90,90)
pincel.fillStyle = "black"
pincel.fillRect(130,125,70,100)
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pincel.fillRect(90,170,40,110)
pincel.fillStyle = "black"
pincel.fillRect(200,170,40,110)
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