Class 9 Maths Euclid Geometry Introduction

Introduction

The word ‘geometry’ came from Greek words ‘geo’, meaning the ‘earth’, and ‘metrein’, meaning ‘to measure’. Geometry appears to have originated from the need for measuring land. This branch of mathematics was studied in various forms in every ancient civilization, be it in Egypt, Babylonia, China, India, Greece, the Incas, etc. The people of these civilizations faced several practical problems which required the development of geometry in various ways

Egyptians: River Nile used to overflow & whipped out boundaries between adjoining fields of different land owners every year. After the flooding, these boundaries had to be redrawn. For this purpose the Egyptians developed a number of geometric Techniques & rule for calculating simple area & also for Simple construction. They used the knowledge of geometry to construct canal, granaries, pyramids etc.

Indians: Indian subcontinent excavations at Harappa & Mohenjo-Daro show that Indus Valley Civilization (3000 BC) made extensive use of Geometry. It was highly planned society. Roads were parallel to each other & had drainage system, this prove that town dwellers were skilled in Geometry.

The geometry was being developed & applied everywhere in the world, but it was happening in unsystematic manner. There geometry knowledge was passed from one generation to other orally or through palm leaf messages.  Iraq or Babylonia, Egyptians & Indians used geometry for practical purpose & did a very little to develop it as a systematic Science. E.g.  They accepted the fact that diameter of a circle divides the circle into 2 half, but never thought of finding out why?

But, in Civilization like Greece, the emphasis was on the reasoning. Greeks were interested in establishing the truth of statements they discovered by deductive reasoning. Greek mathematician Thales is credited with giving first known theorem called Thales theorem in around 600BC which gives Proof for why Circle is bisected by its diameter. Other popular theorem by Greeks is Pythagoras Theorem in 572 BC. Euclid compiled these entire existing theorems in a book called “The Elements”. Some of the famous Greek Mathematicians are shown below.

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