<canvas width="600" height= "400"> </canvas>
<script>
var tela= document.querySelector("canvas");
var pincel= tela.getContext("2d");
pincel.fillStyle= "lightgrey";
pincel.fillRect= (0,0,600,400);
pincel.fillStyle= "green";
pincel.fillRect= (0,0,200,400);
pincel.fillStyle= "red";
pincel.fillRect= (400,0,200,400);
pincel.fillStyle= "yellow";
pincel.beginPath();
pincel.moveTo(300,200);
pincel.lineTo(200,400);
pincel.lineTo(400,400);
pincel.fill();
</script>
