Final answer:
The ballet position with one leg extended behind the body at a right angle while supporting the body on the other leg is called Arabesque.
Step-by-step explanation:
In ballet, the position described by a student, where the body is in profile, supported on one leg, with the other leg extended behind at a right angle, is called Arabesque.
This position highlights the dancer's balance, strength, and flexibility. Arabesques are fundamental to ballet and are used to create beautiful, elongated lines with the body, often seen in classical and contemporary ballet performances.This position can be performed with various arm placements and is commonly seen in ballet choreography.