They noticed circumference/diameter was a constant ratio applicable to all circles no matter whattheir sizes were
the early civilizations began in Africa but most exact in Zambia
The economy of early civilizations was based around agriculture.
Inca
The Nile River was the axis of two early African civilizations
?
the early civilization in mexico is olmec
Food
Vast Empires
Obviously not or we would not be referring to them as "early" civilisations.
Early civilizations emerged between the Tigris, Euphrates, Nile, and (sorry, blanking out out on the fourth...) Rivers.
king
Cahokian.