Final answer:
Marius Petipa is renowned for a formulaic approach to classical ballet which includes a grand pas de deux, variations, and ensemble dances, but there isn't a specific term that names this structure.
Step-by-step explanation:
The term referring to Marius Petipa's formula for creating perfect classical ballet is not explicitly named in ballet vocabulary, but Petipa is well-known for developing the structure of classical ballet performances that typically include a grand pas de deux, which is a dance for two featuring a sequence of entrée, adagio, two variations (one for each dancer), and a coda.
This is often part of a larger framework that involves variations (solo dances) and ensemble dances in a highly structured format. Marius Petipa is celebrated for his contributions to classical ballet, having choreographed many works that contain this formulaic approach, including ballets such as 'The Sleeping Beauty' and 'Swan Lake'.