the above example is too simple, although, we can imagine a more
complex one such as as geometry applet extension wich allows you to
define the carachteristics of a given geometrical construction and
then the user can interact with it.
Imagine a geom. construction with some of the lengths and angles
undetermined (so, denoted by literals). The user (maybe a student at
wikiversity) could then click and drag vertices in order to see how
the whole construction conforms to the lenght and angle variations.
This would provide greater flexibility and understanding than what we
can get today from geometry books and blackboards (with their static
images of these geom. constructions).
Juca