> Where do you get that? An easy analogy to explain why curved surfaces are stronger: imagine an egg that is a cube instead of a spheroid. You see how an eggs

> Where do you get that? An easy analogy to explain why curved surfaces are stronger: imagine an egg that is a cube instead of a spheroid. You see how an eggshell cube would be vastly more brittle than an egg, right? > chose these flat surfaces in steel precisely for their lower cost, solidity and ease of manufacturing To make an equivalently robust structure out of straight edges you need the steel to be much, much thicker. So yes on 'solidity', but no to the other two claims.