var canvas = document.getElementById('loading')
var ctx = canvas.getContext('2d')
canvas.width = 800
canvas.height = 800

function Ellipse(context, x, y, a, b) {
    context.save();
    var r = (a > b) ? a : b;
    var ratioX = a / r;
    var ratioY = b / r;
    context.scale(ratioX, ratioY);
    context.beginPath();
    context.arc(x / ratioX, y / ratioY, r, 0, 2 * Math.PI, false);
    context.closePath();
    context.restore();
    context.lineWidth = 3
    context.strokeStyle = '#3E8CDA'
    context.stroke();
  context.rotate(60 * Math.PI / 180)
}

Ellipse(ctx, 400, 400, 200, 60)