If you look at the man-made objects around you, you will see that almost all of them are either rectangular, or parallel and perpendicular. There are a few circles here and there, but the overwhelming trend in basically everything humans make now is the rectangle. This is true from the computer user interface that you're looking at now and the typography in it all the way up to the shape of building blocks in your city, and if your city is completely planned, to the shape of large sections of it as well, and the fields around it. Even some administrative borders are also rectangular, which seems like the only geometric trend with these.

The product and graphic designers apparently only follow this trend and make everything rectangular because that's what it looked like when they started to work with a particular medium. They didn't probably set the trend.

You could argue that rectangles are easier to pack together, but triangles and hexagons are just as easy to pack, and there are numerous other shapes, polygonic or curved, that pack perfectly well.

The concept of rectangles even applies to the third dimension and there most things are box like, our fridges, houses etc.

If a list were to be prepared of the primary motivations for such rectangular practise, then what would top that list ?

Moreover, the question also applies to the relevance of such motivations in the current age of 3D printing, and modular and adaptive architecture.

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    $\begingroup$ Generally it is easier to manufacture straight lines (implying rectangular) and to a lesser extent circles than freeform shapes. Rectangles also have other advantages depending on application such as better stacking for boxes. $\endgroup$
    – nivag
    May 12 '15 at 9:32
  • 2
    $\begingroup$ I have put this question on hold as it is overly broad and not a good fit for the StackExchange Q&A format. $\endgroup$
    – user16
    May 12 '15 at 13:56
  • $\begingroup$ This does look pretty broad. What do you mean by "your particular field?" If this is a poll, it's not appropriate - but if it's restricted to structures, as implied by your choice of tags, then I think it's okay. $\endgroup$
    – Air
    May 12 '15 at 15:59
  • $\begingroup$ Coming from the field of mechanical construction, I can tell you that there are mainly economic reasons. Example: Triangular rooms would have small volume compared to surface area -> more work for rendering the walls. Hexagonal rooms have good volume per surface area, but there are more edges which also means -> much work. And sure, it is a matter of state-of-the-art of construction and production technology. If you build a house with a 3d printer, straight lines/plane walls, right angles matter less. But then you also have to have curved furniture, which impairs modularity (again: cost). $\endgroup$
    – oliver
    Jun 9 '18 at 4:58


The primary reason is gravity. When humans first started building things structures that were perpendicular to the ground stayed up more. Stacking rocks for example, the straighter you could get it the more stable it would be, therefore the more 'square' the rocks you used, the easier it would be to get it straight. This has not changed, while it's possible to build walls at an angle, these need to be stronger and have more support. Actually if you build a long enough 'rectangular' structure, the top wouldn't be flat, it would bend with the curvature of the Earth. However, at scales we deal with on a day-to-day basis, the easiest shape to build with is rectangular.

Triangular structures can also be strong, but you get less usable space inside the structure for the same amount of material used.

Human devices

Gravity comes into it again, though indirectly. Also geometry plays a big role in what shape our human devices are.

Due to gravity, there are lots of things to see on the surface of Earth, such as trees, rocks, wild animals, food, etc. but not all that much up in the air and downwards there is just the ground. As we evolved, it was more important to see things to the left and right than up and down, such as predators or potential food. So we evolved two eyes, arranged horizontally, giving us a better field of vision in the horizontal plane than the vertical one. Our arms and hands also evolved to allow us to manipulate things horizontally more than vertically. This means if you're looking at something or interacting with it (such as your monitor and keyboard) it's much easier to do so in a horizontal direction.

An arc shape (similar to the shape a car windscreen wiper makes) might actually be more ideal than a rectangle for interacting with, but it is more difficult to manufacture, so ease of manufacturing also comes into it. We do have curved interfaces, but generally when we need to pack lots of things into a small yet accessible space, such as a car dashboard, or an air-traffic-controller's desk, where function is more important than simplicity.

Rectangles are much less universal in smaller human devices. Circles can also be simple to make, for example mugs/vases/bowls on a potters wheel, table-legs on a lathe. This is where geometry comes in. If you want to enclose something, for example hold tea in a mug, using the same amount of material you can hold more with a circular shape than a square one. However if the purpose is to spread things out, to make them accessible (for example words on a page or items on a table) moving them away from each other at right angles will get them further apart for a shorter move-distance. So the function plays a much bigger role than physical viability for smaller items.

Design for aesthetics does of course also affect things, but they need to remain functional otherwise they would become useless, so this limits what can be done in this regard and guides the shape of things around us.

  • $\begingroup$ This is unsatisfactory, and I haven't yet found a satisfying answer to my question, but it is the more helpful of the two, and has some interesting ideas. $\endgroup$
    – Denis
    May 26 '15 at 14:45
  • $\begingroup$ There's a problem that probably gets in the way of answering questions like this, in that humans are assumed to do things for a purpose, and are rational in doing so. This assumption is traditional and unrealistic. This whole rectangular epidemy is probably in large part due to mindless imitation, but I'm interested in finding the other part of it, the reason it started. $\endgroup$
    – Denis
    May 26 '15 at 14:52
  • $\begingroup$ @Denis You might get some good insights on the WorldBuilding site with a question along the lines of "under what evolutionary/cultural conditions would an intelligent species evolve to make primarily triangular 2D tools such as tables, monitors, photo frames, etc." as those guys are great at thinking about the root causes of things like this. $\endgroup$
    – jhabbott
    May 30 '15 at 20:38

In ancient times roundhouses were constructed and are still constructed in predominantly lesser developed countries.

One issue with roundhouses is, once constructed they can't be extended laterally and retain the same shape. Rectangular buildings can be easily extended and most of the original structure can remain - knock down one wall and extend while the other three walls remain unaffected.

In terms of usable floor space the corners of triangles usually become wasted or unusable space, whereas the corners of rectangular floored rooms can be used to their maximum potential easily. Also for the same amount of floor space provided by a rectangular room/building would require a larger triangular room/building.

Constructing rectangular rooms or buildings is easy because the tools required to ensure the corners are right angles are easily made and readily available - such a builders squares or set squares.

The construction of a structures with more sides than a rectangle or square requires beams and other materials to be cut at specific angles for which tools need to be made; this adds to the cost of construction.

Also, by using more than four walls, more wall materials are required; which adds even more cost. Also, more walls means more time required to construct which means more cost.

Circular rooms or buildings are more difficult to make because systems have to be devised to ensure true circles are constructed and such structures are more time consuming to make.

When it comes to structural analysis prior to construction, circles, ellipses and any shape with a curve are difficult to analyze compared to triangles and rectangles.

Rectangular structures are easier and cheaper to construct that structures using different floor shapes.


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