Exercise : What's the output?

What kind of output figure will be drawn by the following code?

DrawingPanel panel = new DrawingPanel(200, 200);
Graphics g = panel.getGraphics();
for (int i = 0; i < 20; i++) {
    g.drawOval(i * 10, i * 10, 200 - (i * 10), 200 - (i * 10));
}