Wind resistance depends not only on surface area but also on shape, because shape controls how air flows around an object and how much push it absorbs. A curved surface lets air slide past with less force, while a flat face catches the full push of the moving air. In one wind-tunnel experiment, the rectangular model topples at the lowest wind speed whereas the circular model withstands the highest speed before collapsing, demonstrating that rounded cross-sections reduce the air's push significantly.

Shape determines how air flows around a structure and how much force it absorbs. When you mount four polystyrene models — rectangular, triangular, circular, and oval — inside a plywood wind tunnel and gradually increase fan speed, the rectangular model topples first. Its flat face meets the air head-on, concentrating force directly against it. The circular model withstands the highest wind speed before collapsing, because air moves smoothly around its curved surface and spreads that force instead of focusing it in one place.