Marcus du Sautoy visits an ancient Indian observatory, and explores how Indian mathematicians used trigonometry to make celestial observations. Using examples in right angled triangles, du Sautoy looks at how it can be worked out how much further the sun is from the earth than the moon.

This clip is from:
The Genius of the East
First broadcast:
13 October 2008

As enrichment for a series of lessons on the practical uses of trigonometry.