Double-click on the movie to PLAY.

Click once to PAUSE.

RELOAD the page or double-click to return to the START of the movie.

Point A i

In this movie we move point A along a line parallel to BC (BC is the invariant line of the shear).

We pause at three postitions that we label A1, A2 and A3.
The movie then reverses and hides the three points again.
You might ask
- Can you remember the position of the three points?
- What is special about the points?
- Are there other such points?

On the next page we show the same movie but with the resulting base and height of triangle ABC highlighted for the three positions of A.