Can anyone explain the relationship between 4:3 and 16:9? I know 16:9 is each number in 4:3 squared, but is there a geometric reason/interpretation for this choice?
The squared relationship is actually pure coincidence. The dude who proposed the next popular ratio took all of the common presentation ratios (like 4:3 for TV, 1.85:1 for film, etc.) and laid them all on top of each other. The overlapping sweet spot was just about 16:9.
