[Pramāṇa](https://indike.org/pramana/) › [Studies](https://indike.org/pramana/ins) › [Science, technology and education](https://indike.org/pramana/ins.science) › [The Science of the Shulba: A Study in Early Hindu Geometry](https://indike.org/pramana/ins.science.datta-1932) › c22.9 # The Science of the Shulba: A Study in Early Hindu Geometry c22.9 The Science of the Śulba: A Study in Early Hindu Geometry c22.9 - **Language:** English ### [c22.9](https://indike.org/pramana/ins.science.datta-1932.c22.9) \*Rectilinear Figures\*.—In the \*Sulba\*, we discern two different systems of nomenclature for the rectilinear geometrical figures.⁴ In one system the naming is according to the number of angles or corners in the figures, and the names are formed by the juxtaposition of the number names with \*aśra\* or \*asra\* which ordinarily means "corner," "angle," \*e.g.\*, \*tryasra\* ("triangle"), \*caturasra\* ("quadrangle"), etc. These names were introduced in the time of the \*Śrauta-sūtra\* (\*c.\* 2000-1500 B.C.). Still older names were compounds ending with \*srakti\* (= "angle," "corner"). Thus the name \*catuḥsrakti\*, which literally means, the "quadrangle," occurs in the \*Vājasaneyī Saṃhitā\*, \*Taittirīya Saṃhitā\*, \*Śatapatha Brāhmaṇa\*, \*Āpastamba Śrauta\*, \*Baudhāyana Śulba\* and other works. In the \*Ṛgveda\*, we find the term \*navasrakti\* referring to the "nine corners" of the heaven. In the \*Kātyāyana Śulba Pariśiṣṭa\*,¹ we have compound names for rectilinear figures ending with \*karṇa\*. The Sanskrit word \*karṇa\* means the "ear." Applied to geometrical figures, it implies the "angle"; hence \*trikarṇa\* = "triangle," \*pañcakarṇa\* = "pentagon." The word \*karṇa\* degenerated into \*koṇa\* in the \*Prākṛta\* languages. So in the Ardha Māgadhī work \*Sūryaprajñapti\*,² we get the names \*trikoṇa\* (= "trigonon"), \*catuṣkoṇa\* (= "tetragonon"), \*pañcakoṇa\* (= "pentagon") etc. These terms are, however, accepted in later Sanskrit literature.³ The term \*aśra\* or \*asra\* in a compound name sometimes denotes the "side". Thus Baudhāyana once described a square as \*catuḥsrakti\* ("four-cornered") and \*sama-caturasra\* ("equi-four-sided").⁴ So the terms \*tryasra\*, \*caturasra\*, etc., will also mean respectively "trilateral," "quadrilateral," etc.⁵ Thus we get a second system of naming retilinear geometrical figures according to the number of sides they possess. - [Previous: c22.8](https://indike.org/pramana/ins.science.datta-1932.c22.8) - [Next: c22.10](https://indike.org/pramana/ins.science.datta-1932.c22.10) - [Up: c22](https://indike.org/pramana/ins.science.datta-1932.c22) ## Linked texts (6) - [Āpastambaśrautasūtra](https://indike.org/pramana/in.vedanga.kalpa.srauta.apastamba) — Āpastamba, Sanskrit - [Taittirīyasaṃhitā](https://indike.org/pramana/in.veda.samhita.krsnayajur*taittiriya) — Sanskrit - [Baudhāyanaśulbasūtra](https://indike.org/pramana/in.vedanga.kalpa.sulba.baudhayana) — Baudhāyana, Sanskrit - [Vājasaneyisaṃhitā](https://indike.org/pramana/in.veda.samhita.suklayajur*vajasaneyi) — Sanskrit - [Ṛgvedasaṃhitā](https://indike.org/pramana/in.veda.samhita.rg) — Sanskrit - [Śatapathabrāhmaṇa](https://indike.org/pramana/in.veda.brahmana.satapatha) — Yājñavalkya & Śāṇḍilya (Vedic teacher), Sanskrit --- Source: [https://indike.org/pramana/ins.science.datta-1932.c22.9](https://indike.org/pramana/ins.science.datta-1932.c22.9) · Pramāṇa