Roll angle refers to the rotation of an object around its longitudinal axis, which runs from the front to the back. This measurement is crucial in various fields, including aviation and automotive engineering, as it helps determine how much an aircraft or vehicle tilts to the side during maneuvers. In aviation, for instance, the roll angle is essential for maintaining balance and control during flight. Pilots use instruments to monitor the roll angle, ensuring that the aircraft remains stable and can perform turns safely. Understanding roll angle is vital for both safety and performance in aircraft and vehicles.