A rope stretched along the length of the diagonal produces an area which the vertical and horizontal sides make together.
1.the Śrautasûtra, probably in 19 Praśnas (questions),
2.the Karmāntasûtra in 20 Adhyāyas (chapters),
3.the Dvaidhasûtra in 4 Praśnas,
4.the Grihyasutra in 4 Praśnas,
5.the Dharmasûtra in 4 Praśnas and
6.the Śulbasûtra in 3 Adhyāyas.
The cord which is stretched across a square produces an area double the size of the original square.
1. books.google.co.in/books?id=DHvTh…
2. sacred-texts.com/hin/sbe14/sbe1…
3. S. Balachandra Rao, Indian Mathematics and Astronomy: Some Landmarks. Jnana Deep Publications, Bangalore, 1998. ISBN 81-900962-0-6
5. mathshistory.st-andrews.ac.uk/Biographies/Ba…
6. mathshistory.st-andrews.ac.uk/HistTopics/Ind…
7. mathshistory.st-andrews.ac.uk/Projects/Pearc…
8. B.B. Dutta."The Science of the Shulba".