Strong shapes
Design & Technology · Early Years · The School
The triangle
Push the corner of a paper square and it collapses into a diamond. Push a triangle and it holds — the sides cannot change length, so the angles cannot change either. That is why triangles appear in bridges, roofs, cranes and pylons everywhere you look.
Making a square rigid
Add one diagonal strip across a floppy square and it becomes two triangles. It stops collapsing at once. This piece is called a BRACE, and adding one is often the whole solution to a wobbly model.
Tubes and folds
Roll a sheet of paper into a tube and it holds real weight standing up, though the flat sheet holds none. Fold paper into a zigzag and it stiffens the same way. Shape is doing the work here, not material — you have added no thickness at all.
Lay a flat sheet of A4 across a gap between two mugs and put a book on it: it collapses. Now roll the SAME sheet into a tight tube, stand it upright, and rest the book on top: it holds. Then fold another sheet into a concertina and lay it across the gap — it holds a book too. Same paper every time. The shape did the work.