Which of the following angles is not considered part of beam geometry?

The rotor angle is not considered part of beam geometry. In the context of radiographic imaging, beam geometry involves the orientation and positioning of the x-ray beam relative to the object being imaged and the detector. This includes vertical angles, horizontal angles, and diagonal angles, all of which describe specific orientations of the beam as it interacts with the subject and the imaging receptor.

The vertical angle denotes the up or down tilt of the x-ray tube, impacting the path of the beam through the object and helping to visualize anatomical structures in a particular plane. The horizontal angle describes side-to-side movement of the beam, which also affects the projection and geometrical representation of structures within the body. The diagonal angle refers to an inclination between the vertical and horizontal planes, often used when specific projections are required for certain views.

In contrast, the rotor angle pertains more to the motion or position of the x-ray tube or the imaging system components rather than the beam's geometric properties related to its path and orientation during image acquisition. Thus, it does not fit within the classification of beam geometry angles impacting image quality and interpretation.