<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, 30);
pincel.lineTo(30, 200);
pincel.lineTo(300, 370)
pincel.lineTo(570, 200);
pincel.fill();
pincel.fillStyle = 'darkblue';
pincel.beginPath();
pincel.arc(300, 200, 110, 0 , 2* 3.14);
pincel.fill();
</script>
