<!DOCTYPE html>
<html lang="pt-BR">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Circulo</title>
</head>
<body>
<canvas width="1200" height="600"></canvas>
<script>
var tela = document.querySelector("canvas")
//tela.innerHTML('Vitor')
var pincel = tela.getContext('2d') // https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/getContext
pincel.fillStyle = 'black'
pincel.fillRect(0,0,1200,600); //Preencha um retangulo fillRect() coordenadas do canvas 600 largura por 400 altura
pincel.fillStyle = 'blue' // PROPRIEDADE fillStyle https://www.w3schools.com/tags/canvas_fillstyle.asp
pincel.fillRect(0,0,400,600);
pincel.fillStyle = 'purple';
pincel.fillRect(800,0,400,600);
pincel.fillStyle = 'yellow'
pincel.beginPath(); // Começa um novo caminho
pincel.moveTo(400,600);
pincel.lineTo(600, 400);
pincel.lineTo(800, 600);
pincel.fill();
pincel.fillStyle = 'orange'
pincel.beginPath();
pincel.arc(1000,200,150,100, 2 * 3,14);
pincel.fill();
pincel.fillStyle = 'black'
pincel.beginPath();
pincel.arc(200,200,50,100, 2 * 3,14);
pincel.fill();
pincel.fillStyle = 'white'
pincel.beginPath();
pincel.arc(600,200,100,100, 2 * 3,14);
pincel.fill();
</script>
</body>
</html>