Final answer:
Body positions for cutting a triangular long layered haircut typically include sitting upright, leaning slightly forward, and tilting the head to the side for better access and accuracy.
Step-by-step explanation:
The typical body positions used when cutting a triangular long layered haircut are not explicitly mentioned in the provided reference information. However, generally speaking, during a haircut, the stylist would require the client to maintain a posture that allows accuracy and evenness in the haircut. The common positions include sitting upright to ensure that the hair hangs naturally and evenly, leaning slightly forward can be used to cut the nape area or for better access to certain layers, and occasionally tilting the head to the side to help achieve the desired angle for layering. The provided reference information describes different anatomical positions and movements, which don't directly apply to the context of hairstyling.