Hours of Entertainment (Pew pew!)

Hey did you know underclassmen are almost as easy to entertain with laser pointers as kittens? It's true.

This challenge has had them going on and off for hours.

Hold this:

And move your body from one side of this board to the other:

while keeping the lasers on the stars. (There is a green Expo-marker star drawn on each side of the board.)

Other rules:

• no changing the angle
• hold the vertex against your sternum
• always face the board, and no one stands between you and the board (safety, you know.)

A few of them are getting pretty good at it, so we appointed another kid to trace his path with chalk on the floor.

The children. They have some questions.

I know there are boring ways to get this point across with paper and pencil, but LASERS. THAT'S WHY.

Update: David Petersen made a Geogebra file to illustrate what is happening.