Introduction to Euclid’s Geometry Class 9 Notes

Introduction to Euclid’s Geometry Class 9 Notes: Chapter 3

What is Euclid’s Geometry?
The word “geometry” comes from the Greek words “geo”, which means the “earth”, and “metrein”, which means “to measure”. Euclidean geometry is a mathematical system attributed to Euclid a teacher of mathematics in Alexandria in Egypt. Euclid gave us an exceptional idea regarding the basic concepts of geometry, in his book called “Elements”.

Euclid listed 23 definitions in his book “Elements”. Some important points are mentioned below:

• A line is an endless length.
• A point is one that which has no part.
• A line which lies evenly with the points on itself is a straight line.
• Points are the ends of a line.
• A surface is that which has breadth and length only.
• A plane surface is a surface which lies evenly with the straight lines on itself.
• Lines are the edges of a surface.

Euclid realized that a precise development of geometry must start with the foundations. Euclid’s axioms and postulates are still studied for a better understanding of geometry. Please refer  Introduction to Euclid’s Geometry Class 9 Notes for more revision notes.