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.

Movie A4

In this movie, the side AD again decreases from 11 units long down to 0, but the movie pauses at various salient points to help students think about the relationship between AD (and AB) and the size of the square EFGH. You can of course pause the movie indefinitely at these points.

On the next page we look at a related (and more challenging) task, where ABCD is a parallelogram rather than a rectangle.
However, you might first want to use this JAVA worksheet to explore the current task in a more interactive way.