<canvas width="600" height="400"></canvas>
<script>
var tela = document.querySelector("canvas");
var pincel = tela.getContext("2d");
pincel.fillStyle = "green";
pincel.fillRect(0,0,600,400);
pincel.fillStyle = "yellow";
pincel.beginPath();
pincel.moveTo(300,50);
pincel.lineTo(50,200);
pincel.lineTo(550,200);
pincel.fill();
pincel.fillStyle = "yellow";
pincel.beginPath();
pincel.moveTo(300,350);
pincel.lineTo(50,200);
pincel.lineTo(550,200);
pincel.fill();
pincel.fillStyle = "blue";
pincel.beginPath();
pincel.arc(300,200,100, 0,2 *3.14)
pincel.fill();
</script>
