English: The design principle of Hindu temples extensively uses circles and squares - both in their horizontal layout and vertical spire design. This is almost universal in ancient Hindu temples found in India, as well outside South Asia. Designs that use harmonic ratios other that perfect square and circle are known, but these too are precise mathematical series and ratios embedding squares and circles inside rectangles (1:2, 1:3, 2:3, 2:5, etc).

For spires rising towards the sky, above the Brahma padas of Hindu temples, turning-square and circumscribing circle geometry is very common (shown). This is both a structural design derivation as well as representative of philosophical beliefs of Hindus. These are described in ancient Sanskrit texts called Vastu sastras (science of dwelling) - the source of above drawing.

At the center of these squares and circles, underneath the spire is the main deity of the temple (visible) as well as the Purusa (Universal Principle with no form, only knowledge and meaning, reflecting Truth and Reality for Hindus).

For further discussion of spire design principles in English, see publications by Michael W. Meister and by Stella Kramrisch. For example:

Title: Mountain Temples and Temple-Mountains: Masrur

Author: Michael W. Meister

Publication: Journal of the Society of Architectural Historians, Vol. 65, No. 1 (Mar., 2006), pp 26-49