क्षेत्रगणितम् · Chapter Overview
From The Brāhmasphuṭasiddhānta, taught by Acharya T Krishnatrey. This lesson is free to read.
<pre data-block="statement">What this chapter covers | Chapter 12 (Gaṇitādhyāya) is Brahmagupta's mathematics of figures. Its jewel is "Brahmagupta's formula" for the exact area of a CYCLIC quadrilateral — one whose four corners lie on a circle — which generalises Heron's formula for the triangle. He also treats the diagonals of such a quadrilateral, right triangles with rational sides, and the circle. This is original geometry of the first rank.</pre>