New Delhi, July 11 - Bharatnatyam, the classical dance style from Tamil Nadu, is all about mathematics after all... as the audience discovered through a dance-drama by Indian American Viji Rao and her troupe from Philadelphia.

Called 'Prayog: A Dialogue between Dance and Mathematics', the performance at the Kamani Auditorium here Friday evening probed the numbers and the cosmic geometric shapes that form the core of this ancient dance form.

The dance-drama, performed by a five-member ensemble of mostly American women of Indian origin, focussed on the nodal geometric shapes, natural angles that the axis of the body makes with the limbs while dancing and postures from temple sculptures, through short choreographies.

It was presented by Viji's Philadelphia-based Three Aksha Institute of Performing Arts and hosted by the Indian Council for Cultural Relations.

Historians say Bharatnatyam originated in the temples of Thanjavur in Tamil Nadu and the modern form of the dance continues to draw inspiration from the temples of south India.

Some of the compositions in 'Prayog' used circus techniques like the ribbon dance to highlight the natural triangles, angles and parallelograms that the body makes while dancing, with the help of white ribbons.

The themes were everyday -- from the ritualistic 'shringar' to the invocation of the gods, rhythms of nature, dance of the peacocks, rain, journey of light and drawing of water from a river. But every motion used the cardinal numbers 3, 4, 5, 7 and 9 to arrive at a figure of 32, which is the basic numerical structure of Bharatnatyam body postures and compositions.

'I wanted to show the typical traditional nuances of Bharatnatyam, classical choreography and the links between the dance and mathematics,' 31-year-old Viji, the director of the Three Aksha Institute that teaches the Kalakshetra style of Bharatnatyam, told IANS.

Viji, who studied modern ballet in a dance company in Britain for 11 years after learning Bharatnatyam in India, said the idea to show the dialogue between Bharatnatyam and mathematics was prompted by the fact that 'people often talk about math in dance; but no one has ever explored it'.