Havan Kund of prescribed form and size are meant to hold sacred fire to which oblations were offered. Their sections represented various geometrical figures such as circle, semi-circle, polygon (triangle, square, etc.) and forms resembling lotus flower and leaf. In order to achieve certain desired objectives Yagyas were performed. There are various forms of Havan Kunds Such as Ardhchandrakar, Kurmaciti (tortoise) for victorious carrier in Brahmalok, etc.

There are well established sutras and traditions of drawing geometrical figures involving various forms and shapes based on mathematical practice.

The objectives of Yajya / Havan are for Success, business, wealth, desire of worldly things, son, freedom from diseases, salvation, while construction of temple or any construction, reducing planetry effect, etc.

Agni Puran Chapter 24 mentions 3 types of Havan Kunds 1. Square, 2. Circle and 3. Semi-circle. Many sort of shapes were later on added. About 200 Kund manuals are listed in famous New Catalogues Catalogorum (Vol. 4 Chennai, 1968).

The dimensions of Kunds must be constructed accurately otherwise it may give adverse effect i.e. if the area is more than prescribed amount it gives diseases and if the area is less than mentioned it brings poverty.

Certain aspects in calculations of Havan Kunds need discussion and some require advance mathematics. The reason behind this is that people have translated the sutras according to their understanding and then done calculations depending on the sutra. This is why the Yaav and Yooka calculations differ from one book to another. Here, we cannot say that one book is right and another is wrong as it all depends on the method of calculations used.

The subject of Havan Kund can be found in Sulba Sutra which is oldest mathematical manuals of Bharat.