You can also peel the label of a tin (can) of baked beans in your cupboard to see the the ripples added for rigidity.

as a bonus, they make canned cranberry sauce visually appealing on the Thanksgiving platter :)

Ever notice there’s a subtle fold in the shape of an “x” in the middle of the sheet metal panels that make up ductwork?

Undulations for rigidity are everywhere!

If it wasn’t for fashion it would probably be the most popular building material for roofs. Make your roof out of that and at an angle and you probably never worry about leaks for decades.

It's all over the place in impoverished areas, often with a bunch of rocks or tires on top to weight it down. If you actually stay in such a structure though, it quickly becomes apparent how little it offers in the way of thermal or acoustic insulation. The sound in a heavy rainstorm can be deafening.

You can mitigate the issues with proper design, but at that point may as well use a real metal roof or a prebuilt.

Roof tiles are just that, but made of a material that stands water much better than than any metal. In any case, corrugated roofs made of asbestos where really popular until people realized they were not good for their health.

Car floor tunnels serve the same purpose. Increase rigidity at low material cost.