Menggambar Lingkaran di javascript

function draw() {

    // draw the colored region

    mainContext.beginPath();

    mainContext.arc(200, 200, 93, Math.PI / 2, Math.PI, true);

    mainContext.fillStyle = '#FF6A6A';

    mainContext.fill();

     

    // draw the stroke

    mainContext.lineWidth = 20;

    mainContext.strokeStyle = '#FF0000';

    mainContext.stroke();

}

sumber: http://www.kirupa.com/html5/drawing_circles_canvas.htm