Which formation is NOT commonly used in patrols?

The formation that is not commonly used in patrols is the circle formation. In military operations, especially during scouting and patrolling, formations are selected based on their effectiveness for the specific tasks at hand, such as maximizing visibility, defense, and communication among team members.

The column formation is favored for moving along narrow routes as it minimizes the group's exposure while maintaining a linear progression. The line formation allows for maximum frontage and observation, which is particularly useful in open terrain or when anticipating enemy contact. The wedge formation facilitates good protection and allows units to respond quickly to threats from any direction.

In contrast, the circle formation, while it can provide 360-degree security and might be utilized in certain situations for defensive purposes, is not practical for scouting or patrol movements, where speed, maneuverability, and the ability to cover ground are crucial. Therefore, it is typically not considered a standard formation for such operations.