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.