Look at almost any building in the contemporary city, it’s constructed from right angles, assembled into rectangles, assembled into boxes. We expect, in fact, a room to have a rectangular floor, with vertical walls meeting in right angles. Exceptions are either due to architectural fancies or to historical constraints or mistakes.
When a kid draws a house, it looks like a rectangle, with the triangle of the roof on top.
Is this normal? Where does this obsession of the right angle comes from?
The answer is that behind any right angle is hidden a gnomon. We build like this because we are Pythagoras children, living by the rules and categories of our cultural ancestors, the ancient greeks.
(I) In ancient times, or in places far from the greeks (and babylonians), other architectural forms are preferred, like the roundhouse. Here’s a Scottish broch (image taken from this wiki page)
and here’s a Buddhist stupa (image taken from the wiki page)
Another ancient building form is the step pyramid , like the Great Ziggurat of Ur (image taken from the last wiki page)
or the egyptian pyramids, or any other famous pyramid in the world (there are plenty of them, in very different cultural frames).
Here is a Sardinian Nuraghe
Conclusion: round, conical, pyramidal is the rule, there are no right angles there!
Until the greeks: here’s the Parthenon
It is made of gnomons, here’s one (from the wiki page)