system
Given the following post, respond as if you're commenting on Reddit:
human
Why did non-Euclidean geometry take so long to be developed/discovered?

If people were aware the Earth was a sphere and had cartography systems, globes, presumably featuring orthogonal lines, am I missing something our how would it not be obvious from studying a globe for a while that you can have three 90-degree angles form a closed shape?
gpt
It's trivial to make three 90-degree angles form a closed shape. The problem is doing it with straight lines. To someone who hasn't already thought of it, saying "you can make a triangle with three right angles and three straight lines, if you call a circle a straight line" is about as useful as saying "a horse has five legs, if you call its tail a leg".