Did the jury ever "form" or "perform" in Twelve Angry Men?
You should ask your teacher for clarification on those two terms. However, my best guess is that your teacher wants you to consider if the jury members form a unified opinion of "guilty" or "not guilty" and did they perform for each other as they attempted to reach their decision. The answers for those questions are both "yes." The jurors all come from different backgrounds and knowledge perspectives. The evidence is pointed out by jurors to help them reach the "not guilty" verdict--the glasses the witness wore, the train, the knife and how it was held, how common the knife is to get on the street, who heard the screams and when they heard them, etc. One "performance" that is especially memorable is the reenactment of the knife...one juror demonstrates how knives of this kind are held in a fight which comes from his background of growing up on streets just like the one where the defendent lives. Even in the confusion of people wanting to leave in order to make their theatre dates, etc. the jurors do end up proving that there is considerable doubt where the defendent's guilt is concerned. The knife is not so uncommon (one juror had one just like it in his pocket), the witness was half-blind even with her glasses, the train passed between the witness and the crime, and it is possible that another person committed the murder. Without the reenactments (performances) they may have said "guilty" without pause.
The group does form despite the fact that it takes a great deal of discussion and arguing in the jury room before several members of the jury agree to consider the evidence more carefully.
It is through the reluctance of Juror #8 to immediately vote guilty in the jury room that leads to the close examination of the testimony and the evidence. He is the catalyst for the unity that eventually develops in the jury room, which leads to an honest assessment of the evidence and the witnesses.
"The jurors must transcend their political differences and work together to find out the truth. In this sense, the play is a microcosm of democracy at work. Everyone has their say, and everyone works together to further the common good, which, in this case, is the administration of justice."