Double-click on the movie to PLAY.

Click once to PAUSE.

Double-click again to return to the START of the movie.


The green and red lines show the maximum possible heights when we use AC and AB respectively as the base.

So the area increases as we move B to U (left) and then move C to V.

However, as we move C to V, point U also moves. So we can increase the area further by moving B to the new position of U - and then moving C to the new position of V.

What happens to the shape of the triangle as we continue to move B and C in this way? Us this worksheet to find out.