Q. How do I format an MLA citation for a play that is in an anthology?

Follow this format:

Last name, First name. "Title of Play or Work." Title of Collection, edited by Editor's Name(s), Publisher, Year, Page range of entry.

The MLA Handbook Plus gives this example on citing excerpts from a Work Published in an Anthology.

Baudrillard, Jean. Except from "The Precession of Simulacra."  The Norton Anthology of Theory and Criticism, edited by Vincent B. Leitch, 2nd ed., W.W. Norton, 2010, pp. 1556-66.