The greatest tragedy written by Sophocles is Oedipus The King, followed by Antigone.
Oedipus and Antigone - generally known as the Theban plays
Yes.
It is a Tragedy along with Sophocles and Euripides.
The classic tragedy Oedipus Rex was written by Sophocles and first performed in 429 BC. Aristotle proclaimed the play the best Greek tragedy ever written in his book Poetica.
Sophocles
The earliest tragedies, that is to say, tragic plays, were written in Ancient Greece by such playwrights as Aeschylus, Sophocles and Euripides
i'm pretty sure they are Euripides, Aeschylus and Sophocles
Sinclair MacLardy Adams has written: 'Sophocles, the playwright' -- subject(s): Mythology, Greek, in literature, Criticism and interpretation, Tragedy
Over 120 plays
Greek literature boasts three great writers of tragedy whose works are extant: Aeschylus, Sophocles, and Euripides.
Aristotle laid out his theories about dramatic tragedy in Oedipus the King by Sophocles poetics.
It is impossible to answer you question in a line or two. Aristotle wrote a whole book (his Poetics) as he tried to define tragedy. See if you can find a condensed version - you could try looking on t he Internet for 'Aristotle's definition of tragedy' or 'Aristotle's Poetics'. Good luck!