NCERT Solutions for Class 9 Maths Exercise 5.1 Introduction to Euclid’s Geometry in Hindi and English Medium updated for Session 2022-2023. Class 9 Maths solutions are useful not only for CBSE but the State board also. We have solved the questions step by step using suitable postulate and axiom.

## NCERT Solutions for Class 9 Maths Exercise 5.1

### What is Euclid’s Geometry?

Mathematics is concerned about calculation and measurements. Arithmetic consists of things like counting, addition, subtraction, multiplication, and division. We have also learned the branch of mathematics called Algebra.

We were also introduced to geometry in previous classes. Earlier, we studied about lines and angles, and different forms of plane figures. In class 9 chapter 5, an attempt is made to understand a branch of geometry commonly known as Euclid’s geometry.

#### What do we do in Geometry?

The word Geometry has been derived from Geo which means Earth and metrin which means measurement. Though, it is not clear how geometry originated, yet it is generally accepted that it originated from the need for measurement. The earlier civilizations of China, Greece, Egypt, and India faced practical problems while measuring land of different shapes and size. They thought of device which could suitably measure /calculate the area and volume of different types of structures like canals, pyramids and even truncated pyramids.

##### Existence of Geometry in Ancient Civilization

With the help of geometry, we can find out not only the area of basic plane figures, like a triangle, rectangle and square but even the volume of pyramids also. A pyramid, as we know, is a solid figure having a polygon as its base. Whereas the side faces are triangles converging at the top.

In the ancient Indian subcontinent, the Indus valley civilization (about 3000 B.C.), Indians made extensive use of geometry. For example – roads were parallel to each other. The drainage system were well organized, the rooms were of different shapes – but conforming to mathematical designs. It is pertinent to note that the dimension of the bricks used were in the ratio 4:2:1.

###### Application of Geometry in Past

In the ancient India (about 800 B. C) were found manual of geometric constructions. The location of sacred places was according to clearly laid down shapes and areas – to serve as effective instruments while performing spiritual activities. The Shri Yantra is a classic example of the use of geometry to attract energy from the cosmos.

Luckily, the concepts of geometry were passed on from one generation to another through palm leaves. The Babylon’s and Egyptians used geometry for practical purposes, though Greeks were interested in reasoning behind the geometrical statements. The famous Greek mathematicians Pythagoras and Thales were from Greece.