Later on the Romans took from the Greeks the shape of the theatre. But their relief was predominantly flat and they had to create artificial construction, by which they mounted stepwise the seats for the viewers. The theatron was called by them cavea. The orchestra with the Romans had a semi circular shape, the skene was connected with it, and was not separate as in the Greek theatre. It was frequently decorated by statues, while during the Roman Empire the statue of the Emperor was obligatorily put there.
Have a look at the main elements of the Roman Theatre in Ephesus, Turkey by visiting the Funfair and try to put them where they belong to.