When a ball bounces back on the border of a billiard table, its trajectories before and after the impact are in symmetry with respect to the normal line of the border.

If, instead of a rectangular form, the billiard table is bounded
by a curve, the successive bouncings of the ball are often much more complicated, as the
trajectory of the ball depends heavily on the point of the impact. This is
exactly the case for *Elliptic billiards*, where the table is circular or
elliptic. To play it, you have only to click on the billiard table.

Please take note that WIMS pages are interactively generated; they are not ordinary HTML files. They must be used interactively ONLINE. It is useless for you to gather them through a robot program.

- Description: bouncing on a billiard table of elliptic form. WIMS site
- Keywords: interactive mathematics, interactive math, server side interactivity, geometry, symmetry, tangent, ellipse