During alarm responses, which perimeter is established?

• A. 360-degree perimeter.
• B. 90-degree perimeter.
• C. 180-degree perimeter.
• D. No perimeter.

Answer: (A)

A full 360-degree perimeter around the incident scene is established to remove all blind spots and provide complete security coverage in every direction. When an alarm triggers, you can’t assume threats will come from a single side, so surrounding the area allows responders to monitor every approach, control entry points, and move teams safely without leaving gaps for an intruder to exploit. A partial perimeter—such as 90 or 180 degrees—creates openings that attackers could use, while having no perimeter leaves the site entirely exposed. Establishing a complete circle around the site gives the best protection and situational awareness during alarm responses.