what role does 90 degree plays in products and architecture?

Question

why most of the things around us are complementry angles or complmentry angles of 90 degree?

Answer 1

You need a 90 degree angle to create a right triangle. The right triangle is used constantly in architecture and construction for determining elevations, angles and squareness of projects. Everything from foundations to rafters to stairs requires right triangles to get the measurements correct. 90 degree angles literally used everywhere.

Answer 2

A very good question. I make furniture, and one of my sayings is "If you don't have a true right angle, you don't have anything." (I've gone through many "squares" until a I found a true one.)

A right angle (90 degrees) represents balance which is enforced by gravity. It's a harmony between 2 sides. Every other angle will cause 2 lines to diverge or collide. Right angles keep things balanced and in harmony.

Only right angles fit together universally. All other shapes and angles restrict the possibilities of how shapes or structures fit together.

Of course, life and art is a lot more interesting than just a bunch of rectangles, but right angles are a good start.