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.

Method C

Here we have chosen a position for point E and point F.

Before running the movie, try to visualise what happens when we rotate ABCDEF through 90˚ about F.
Is the resulting image too high, too low, too far to the left, too far to the right?
What aspect of the image is correct?

Run the movie.
Now imagine moving F to a better position - would you move it up, down, left or right?

You can explore what happens for different positions of F using the JAVA-worksheet.
Try moving F before rotating and after rotating. Try to predict what happens.