# Mathematician:Jamshīd al-Kāshī

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## Mathematician

Prominent mathematician of the newly-founded Samarkand Institute.

Best known for calculating the value of pi ($\pi$) to $16$ decimal places.

## Nationality

Persian

## History

- Born: c. 1380, Kashan, Iran
- Died: 22 June 1429, Samarkand, Transoxania

## Theorems and Definitions

- The value of pi ($\pi$) to $16$ decimal places
- Law of Cosines (known in France as
*Théorème d'Al-Kashi*(Al-Kashi's Theorem) - Triple Angle Formula for Sine

## Publications

*Khaqani Zij**Sullam al-Sama**The Treatise on the Chord and Sine**The Key to Arithmetic*in which Pascal's Triangle (under the name*Khayyam's Triangle*) is discussed

- 1416:
*Treatise on Astronomical Observational Instruments*

## Other inventions

- Plate of Conjunctions, an analog computing instrument used to determine the time of day at which planetary conjunctions will occur

- Plate of Zones, a mechanical planetary computer

## Also known as

In Persian: **محمد بن محمد بن الحسن طوسی** -- **Ghiyās-ud-dīn Jamshīd Kāshānī**.