This drawings shows the plan, elevation and section of the auditorium of a Vitruvian theatre. It also shows an elevation of the façade of the stage house of the theatre. Like X/4 verso, this drawing is a study for a plate in Barbaro's translation of Vitruvius.
Palladio was very interested in Vitruvius's theatre drawings. He studied theatres in De Archittura, and drew Roman theatres and amphitheatres, such as those at Verona and Pula in Croatia. He used these ancient principles to design the Teatro Olimpico in Vicenza. The major source for this illustration was the ruined Teatro Berga in Vicenza.
The Teatro Olimpico, commissioned in 1580, was one of Palladio's last buildings. In fact it was only designed by Palladio; the majority of the building work was overseen by his sons. Palladio did design the impressive scene front for which the theatre is celebrated, but his design was subsequently greatly altered by Vincenzo Scamozzi, who added a tromp l'oeil effect street scene behind the proscenium. It is this design you see today.