Why do minor arcs have 2 points and major arcs 3 points?

Question

I have no clue what the answer is ive asked many people 10 points for the correct answer...(points will be give to 1st person wit correct answer) Thanx :D

Answer 1

on a circle, the minor arc and the major arc make the complete circle. if the two points of the minor arc are A and C, with B on the major arc, if you didn't have B you would say "arc AC" and nobody would know which arc you meant, minor or major. So by putting the B in there we can tell which is major and which is minor, arc AC is minor, ABC is major.

It could have been the other way around, but since the major arc is larger, why not it have the extra letter?