system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why are right angles 90 degrees instead of 100 degrees? Wouldn't trigonometry be much more intuitive if full circles were 400 degrees?

I am sure that the ancients had a great reason for using 90 degrees to describe perpendicular angles, but it seems that we should be able to make math simpler by evolving to a "metric" system of measuring angles.

EDIT: Thanks for the replies! A history of angles, like the one you all just provided, would make taking trig classes so much more interesting.
gpt
360 has a *lot* more factors than 400, so it's actually more flexible and intuitive to use.

Factors of 400 -

1 x 400

2 x 200

4 x 100

5 x 80

8 x 50

10 x 40

16 x 25

20 x 20

Factors of 360, on the other hand:

1 x 360

2 x 180

3 x 120

4 x 90

5 x 72

6 x 60

8 x 45

9 x 40

10 x 36

12 x 30

15 x 24

18 x 20

We only really use base 10 (that is, you count from zero to nine before adding an additional digit) because we have 10 fingers. It's actually not the most intuitive numbering system at all.