Final answer:
The elevation at which the hair is held when cutting a triangular long layered haircut is 90 degrees.
Step-by-step explanation:
The elevation at which the hair is held when cutting a triangular long layered haircut is 90 degrees.
This means that the hair is held perpendicular to the head during the cutting process. This elevation allows for more control and precision in layering the hair.
By holding the hair at a 90-degree angle, the layers will be cut evenly, creating a balanced and seamless look.