Why was the battle of platea a turning point fo the Greeks?

Answer 1

After destroying Persian sea power at the battle of Salamis, they were able to defeat their army, and so end the attempt by the Persians to incorporate the cities of mainland Greece into the Persian Empire.

Answer 2

We might be able to answer if you ask a sensible question - what plateau are you talking about?

He most likely means the Battle pf Plataea, but that is just a guess.

Good guess - you are more forensic than I. Ok, here goes.

There were two turning points in the Persian invasion of 480-479 BCE - the first and most significant was the battle of Salamis in 480 where the southern Greek fleet destroyed the Persian fleet, the remnant of which retired to Mykale and stayed out of the war. This left the Persian army without its supply line from Asia, and half the Persian army had to be sent home as it could not be supported through the oncoming winter.

The following spring the southern cities were able to send out their armis which they had been keeping at home protecting their cities against the amphibiois threat of the Persian fleet. These armies combined at Plataea to defeat the now half-strength Persian army and its central Greek allies. At the same time the Greek fleet finished off the remaining Persian fleet at Mycale.

Plataea was not the turning point - Salamis was. Plataea and Mycale were the coup de grace.