Āryabhata-II and his Concept of Concave Quadrilateral in Ancient India

Amalkumar Mukhopadhayay
2017 Indian Journal of History of Science  
The aim of this article is to throw light on the concept of concave quadrilateral introduced for the first time in the 10 th century CE by Āryabhaa-II (c.950 CE) in his Mahāsiddhānta (abridged as Mahāsi.) erstwhile unidentified by any other mathematician in the world. The validity of the date of Āryabhaa-II has also been discussed.
doi:10.16943/ijhs/2017/v52i4/49263 fatcat:hkl6xrecknfc5bct2q65pdvude