Indian astronomer and mathematician.

Born: c. 598 AD

Died: c. 670 AD

**Discoveries**

**Astronomical Theory**

**Zero**

In his magnum opus *Brahmasphutasiddhanta*, Brahmagupta was the first known mathematician to document on the arithmetic properties of zero as a number. The concept of zero as a number may have been known in India prior to Brahmagupta. Radiocarbon dating of the *Bakhshali Manuscript* (which included the symbol for zero) has revealed that parts of the document was written in the 4th century AD, the 7th century AD, and the 10th century AD.

**Approximation of Pi**

Brahmagupta used two approximations of pi:

**Pell's Equation**

**Cyclic Quadrilaterals**

Brahmagupta was famous for his studies on cyclic quadrilaterals. He discovered the formula for computing the area of a cyclic quadrilateral with sides

where is the semi-perimeter.

He also discovered the property of orthodiagonal cyclic quadrilaterals, which is called the Brahmagupta theorem.