<meta charsed="UTF-8">
<canvas width="600" height="400"></canvas>
<script>
var tela = document.querySelector('canvas');
var pincel = tela.getContext('2d');
//fundo
pincel.fillStyle = 'green';
pincel.fillRect(0, 0, 600, 400);
pincel.beginPath()
pincel.fillStyle="yellow"
//triangulo
pincel.moveTo(300, 50);
pincel.lineTo(550, 200);
pincel.lineTo(50, 200);
pincel.fill();
//triangulo invertido
pincel.beginPath();
pincel.moveTo(300, 350);
pincel.lineTo(550, 200);
pincel.lineTo(50, 200);
pincel.fill();
//circulo
pincel.fillStyle="darkblue";
pincel.beginPath();
pincel.arc(300, 200, 100, 0, 2*3.14);
pincel.fill();
</script>
