<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(40,200);
pincel.lineTo(560,200);
pincel.fill();
pincel.beginPath();
pincel.moveTo(300,350);
pincel.lineTo(40,200);
pincel.lineTo(560,200);
pincel.fill();
pincel.fillStyle = "darkblue";
pincel.beginPath();
pincel.arc(300, 200, 100, 0, 2*3.14);
pincel.fill();
</script>
