Answer:
A revolving door must have a companion door that is perpendicular and within a close distance.
Step-by-step explanation:
The purpose of the companion door is to maintain the air pressure balance inside the building when people go in and out through the revolving door.
The companion door is usually located next to the revolving door and opens in the opposite direction.
This allows people to enter or exit the building without disrupting the airflow.
Having the companion door close to the revolving door ensures that people can easily access it when exiting or entering.
If the companion door was placed too far away, it would defeat the purpose of having a revolving door in the first place.