Angle Planes measurement

Im using the angle planes extension to try to measure an angle between the lateral semicircular canal and the vestibular aqueduct. I marked the wanted angle in the picture. The extension shows me 3 angles(pitch,yaw,roll), which one of these angles is the one i wanted and how do i know?

You can compute angle between planes in several different ways. If you need angle between plane normal vectors then copy-paste this code snippet in the Python interactor: