As I mentioned in an earlier blog
that the Arabic numbers has the concept of the number of the angles less than 180º...
Unfortunately this theory
was never prooved 100% due to the loss of the original documents when the Viking invaded Baghdad
in that era...
So my notes that I learned about this concept are illustrated in the purple
illustration of numbers (I had to replace the photo)...
And the greenish
illustration is what Littledesire found online
about the same subject...
I care to give you the right information and it's up to you which one sounds better!
Note1: The differences are in the numbers 8 and 9
Note2: Zero is considered no angles and considered also endless number of angles! I think it's Roman origin and some says it's Indian origin! That's why I didn't include it in the Arabic numbers.