I use these forms to introduce structural design. It sets up a really useful discussion in design on the link between materials and form.
If you want to design one of these forms in particular (e.g. structural frame), then you need to choose materials that allow you to create that form (timber can take compression and bending).
Or if you have a particular material available (e.g. stone), then you need to look at and design forms that can be achieved in that materials (compression structures).
