system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Why do trucks that carry liquids have cylindrical tankers? Wouldn't you be able to carry more volume in a rectangular container?
gpt
A cylinder doesn't create weak points, like corners or like the middle of flat sides (which can bulge).

A cylinder uses less surface material to enclose the same volume, compared to a rectangle. (To help understand this intuitively: rounding off the corners saves a lot of material with only a small loss in volume.)