Class 9 Maths — Chapter 5: INTRODUCTION TO EUCLID'S GEOMETRY

What you'll learn

• ▸Historical Development of Geometry
• ▸Euclid's Definitions and Undefined Terms
• ▸Distinction Between Axioms and Postulates
• ▸Euclid's Axioms
• ▸Euclid's Postulates 1 & 2
• ▸Euclid's Postulates 3 & 4
• ▸Euclid's Fifth Postulate (The Parallel Postulate)

Chapter Summary

--- PAGE 1 --- CHAPTER 5 INTRODUCTION TO EUCLID'S GEOMETRY 5.1 Introduction The word 'geometry' comes form the 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 civilisation, be it in Egypt, Babylonia, China, India, Greece, the Incas, etc. The people of these civilisations faced several practical problems which required the development of geometry in various ways. For example, whenever the river Nile overflowed, it wiped out the boundaries between the adjoining fields of different land owners. After such flooding, these boundaries had to be redrawn. For this purpose, the Egyptians developed a number of geometric techniques and rules for calculating simple areas and also for doing simple constructions. The knowledge of geometry was also used by them for computing volumes of granaries, and for constructing canals and p…

Practice Questions from this Chapter

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1. Explain Euclid's first definitions? Get Solution →
2. Illustrate geometry in your daily life? Get Solution →
3. Compare ancient and modern geometry? Get Solution →
4. From which two Greek words does the word 'geometry' originate? Get Solution →
5. In the Indus Valley Civilisation, what was the ratio of length : breadth : thickness for the construction bricks? Get Solution →
6. Who is the Greek mathematician credited with giving the first known proof? Get Solution →
7. What is the name of Euclid's famous treatise which collected and arranged all known geometric work of his time? Get Solution →
8. According to Euclid's definitions listed in the text, what is a point? Get Solution →

Did you know?

• 💡 Euclid's "Elements" was once the most popular book after the Bible.
• 💡 Ancient Egyptians used geometry to restore farm boundaries after floods.
• 💡 Honeybees construct their honeycombs using precise hexagonal geometry.
• 💡 The first known mathematical proof was about a circle's diameter.
• 💡 NASA uses complex geometry to guide spacecraft through space.

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