How many rectangles can you find in this shape? Which ones are
differently sized and which are 'similar'?
If the sides of the triangle in the diagram are 3, 4 and 5, what is
the area of the shaded square?
A tennis ball is served from directly above the baseline (assume
the ball travels in a straight line). What is the minimum height
that the ball can be hit at to ensure it lands in the service area?
Plex lets you specify a mapping between points and their images.
Then you can draw and see the transformed image.