Rays of lights are reflected from the mirror, each ray satisfying the
law of reflection.

It is fun to play with two plane mirrors, multiple images are

Would you like to try it with this java applet?

P.S. I have created [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=569.0]another version of the same applet with EJS[/url] (2007/11/27).

There are two plane mirrors with an initial angle of 120 degree.
Click the green circle and drag the mouse to change the angle.

The red circle (with yellow background) and the blue line on the left of
the mirror , represent the object to be play with.
Click inside the red circle or near the end of blue segment
and drag the mouse to change size/location/orientation
of the object.

Right click the mouse button to show the relations between images.

Rays of light will emit from the red circle if you click mouse button twice.

Find out the light paths and their relations to the images.

Play with it and enter the physics of optics.