The practice of taking an intermission during a play originated during the italian renaissance so that

Intermission was originated during the Italian Renaissance to make the play longer.  Since the introduction of indoor theaters at that time, that were lit with candles, performances had to be altered to replace the spent candles.  They had to do it four times that's why plays were divided into five acts. However, although theaters now are not lit by candles, plays still have at least one intermission to give the audience a chance to stretch their legs; and it also serves as a memento of the Italian Renaissance.