how did the discoveries of the greeks change from the time of pythagoras to the time of eratosthenes? ASAP

In ancient Greek they were primarily using tetra-chords and there was three main standard divisions of these tetra-chords called genus.

In the same era Pythagoras discovers the relationship between intervals and ratios, 3:2 for a perfect fifth is an example. I've also read that the ancient Greeks used Pythagoras findings to help tune the tetra-chords since they spann a perfect fourth. However it got me wondering:

A) Did the ancient Greeks use Pythagoras findings to create the tetra-chord in the first place or did they just use it for tuning later on?

B) If Pythagoras did not have anything to do with the creation of tetra-chords, then who did?

Explanation:

explanation:

a trial judge has broad powers in his courtroom. the judge's decision is usually final for the duration of the trial, and the party's one special type of witness is an expert witness.