Untitled

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Made with Thimble</title>
    <link rel="stylesheet" href="style.css">
  </head>
  <body>
    <canvas id="canvas" width="500" height="300"></canvas>

    <script>
      var canvas = document.getElementById("canvas");
      var ctx = canvas.getContext("2d");

      //desenhando um retangulo
      ctx.beginPath();
      ctx.rect(20,100,50,50);
      ctx.fillStyle = "#00baff";
      ctx.fill();
      ctx.closePath();
    </script>
  </body>
</html>