Ancient Indian geometry is a rich and fascinating field of study, with contributions that have had a lasting impact on the development of mathematics around the world. The treatises and works of ancient Indian mathematicians demonstrate a deep understanding of geometric principles and techniques.

One of the earliest known works on geometry in India is the Sulba Sutras, a collection of texts from the Vedic period (1500-500 BCE). The Sulba Sutras were used by priests to construct altars and other religious structures. They contain geometric rules for constructing squares, rectangles, circles, and other shapes, as well as for calculating areas and volumes.

The Sulba Sutras also contain some of the earliest known examples of Pythagorean triples, and they give a geometric proof of the Pythagorean theorem. Additionally, the Sulba Sutras contain some remarkable results that anticipate some of the concepts and methods of modern mathematics. For example, they contain a geometric construction for a square with the same area as a given rectangle or circle, using an approximation method that is equivalent to finding the geometric mean.

Another important work on geometry in ancient India is the Arthashastra, a treatise on statecraft and economics written by Kautilya in the 4th century BCE. The Arthashastra contains geometric rules for constructing forts, palaces, and other structures, as well as for surveying land and calculating taxes.

In the 5th century CE, the mathematician Aryabhata wrote the Aryabhatiya, a seminal work on mathematics and astronomy. The Aryabhatiya contains geometric rules for calculating the areas and volumes of various shapes, as well as for solving trigonometric problems. Aryabhata also introduced the sine function, which is one of the most important trigonometric functions in modern mathematics.

In the 7th century CE, the mathematician Brahmagupta wrote the Brahmasphutasiddhanta, another important work on mathematics and astronomy. The Brahmasphutasiddhanta contains geometric rules for constructing various figures, including the regular pentagon and the regular hexagon. Brahmagupta also introduced the concept of negative numbers, and he gave a geometric proof of the Brahmagupta formula, which is a formula for calculating the area of a cyclic quadrilateral.

In the 12th century CE, the mathematician Bhaskara II wrote the Lilavati, a treatise on mathematics and astronomy. The Lilavati contains a wealth of geometric knowledge, including rules for constructing various figures, calculating areas and volumes, and solving trigonometric problems. Bhaskara II also introduced the concept of the derivative, which is a fundamental concept in calculus.

The contributions of ancient Indian mathematicians to geometry are numerous and significant. They developed sophisticated geometric techniques that were applied to a wide range of problems, from constructing altars and temples to calculating areas and volumes to solving trigonometric problems. The ancient Indians also made important contributions to the development of algebra and trigonometry, which are essential tools for modern geometry.

The legacy of ancient Indian geometry can be seen in many different areas of mathematics today. For example, the Pythagorean theorem is still one of the most important theorems in geometry, and it is used in a wide variety of applications, from surveying land to constructing buildings. Additionally, the concept of the derivative, which was introduced by Bhaskara II, is a fundamental concept in calculus, which is used in many different fields of science and engineering.

The treatises and works of ancient Indian mathematicians on geometry are a testament to their brilliance and ingenuity. Their contributions to geometry have had a lasting impact on the development of mathematics around the world.