• Skip to main content
  • Skip to primary sidebar
  • Skip to footer
  • NCERT Solutions
    • NCERT Books Free Download
  • TS Grewal
    • TS Grewal Class 12 Accountancy Solutions
    • TS Grewal Class 11 Accountancy Solutions
  • CBSE Sample Papers
  • NCERT Exemplar Problems
  • English Grammar
    • Wordfeud Cheat
  • MCQ Questions

CBSE Tuts

CBSE Maths notes, CBSE physics notes, CBSE chemistry notes

NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry

NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry are part of NCERT Solutions for Class 9 Maths. Here we have given NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry.

Board CBSE
Textbook NCERT
Class Class 9
Subject Maths
Chapter Chapter 5
Chapter Name Introduction to Euclid’s Geometry
Exercise  Ex 5.1
Number of Questions Solved 7
Category NCERT Solutions

NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry Ex 5.1

Ex 5.1 Class 9 Maths Question 1.
Which of the following statements are true and which are false? Give reasons for your answers.
(i) Only one line can pass through a single point.
(ii) There is an infinite number of lines which pass through two distinct points.
(iii) A terminated line can be produced indefinitely on both sides.
(iv) If two circles are equal, then their radii are equal.
(v) In figure, if AB = PQ and PQ = XY, then AB = XY
NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry 1
Solution:
(i) False. In a single point, the infinite number of lines can pass through it.
NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry 2
(ii) False. For two distinct points only one straight line is passing.

(iii) True.
NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry 3
(iv) True.      [∵ Radii of congruent (equal) circles are always equal]
(v) AB = PQ  …(i)
PQ = XY   …(ii)
⇒ XY = PQ
From Eq. (i) and (ii), we get AB = XY

Ex 5.1 Class 9 Maths Question 2.
Give a definition for each of the following terms. Are there other terms that need to be defined first? What are they and how might you define them?
(i) parallel lines
(ii) perpendicular lines
(iii) line segment
(iv) a radius of a circle
(v) square
Solution:
(i) Parallel lines: Two lines in a plane are said to be parallel if they have no point in common.
NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry 4
In the figure, x and y are said to be parallel because they have no point in common and we write, x//y.
Here, the term point is undefined.

(ii) Perpendicular lines: Two lines in a plane are said to be perpendicular if they intersect each other at one right angle.
NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry 5
In the figure, P and Q are said to be perpendicular lines because they intersect each other at 90° and we write Q⊥P.
Here, the term one right angle is undefined.

(iii) Line segment: The definite length between two points is called the line segment.

NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclids Geomentry 5
In the figure, the definite length between A and B is line segment and represented by \(\bar { AB } \).
Here, the term definite length is undefined.

(iv) Radius of a circle: The distance from the center to a point on the circle is called the radius of the circle.
In the adjoining figure, OA is the radius.
tiwari academy class 9 maths Chapter 5 Introduction to Euclids Geomentry 6
Here, the term, point, and center are undefined.

(v) Square: A square is a rectangle having same length and breadth. Here, the terms length, breadth, and rectangle are undefined.

Ex 5.1 Class 9 Maths Question 3.
Consider two ‘postulates’ given below:
(i) Given any two distinct points A and B, there exists a third point C which is in between A and
(ii) There exist at least three points that are not on the same line.
Do these postulates contain any undefined terms? Are these postulates consistent?
Do they follow from Euclid’s postulates? Explain.
Solution:
There are several undefined terms which the student should list. They are consistent because they deal with two different situations-
(i) says that the given two points A and B, there is a point C lying on the line in between them;
(ii) says that given A and B, we can take C not lying on the line through A and
These ‘postulates’ do not follow from Euclid’s postulates. However, they follow from axiom stated as given two distinct points, there is a unique line that passes through them.

Ex 5.1 Class 9 Maths Question 4.
If a point C lies between two points A and B such that AC BC, then proves that AC = \(\frac { 1 }{ 2 }\) AB. Explain by drawing the figure.
Solution:
Given, a point C lies between two points A and B such that AC – BC.
NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry 8
On adding AC to both sides, we get AC + AC = BC + AC
⇒ 2AC = AB ⇒ AC =\(\frac { 1 }{ 2 }\) AB Hence Proved

Ex 5.1 Class 9 Maths Question 5.
In question 4, point C is called a mid-point of line segment AB. Prove that every line segment has one and only one mid-point.
Solution:
Here, C is the mid-point of line segment AB, such that
NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry 9
Let there are two mid-points C and C′ of AB.
AC =\(\frac { 1 }{ 2 }\) AB
AC′ =\(\frac { 1 }{ 2 }\) AB
⇒ AC’=AC
Which is only possible, when C anc C′ coincide.
⇒ Points C and C′ are identical.
Hence, every line segment has one and only one mid-point.

Ex 5.1 Class 9 Maths Question 6.
In the given figure, if AC = BD, then prove that AB = CD.
NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry 10
Solution:
According to axiom 5, we have the whole is greater than the part, which is a universal truth.
Let a line segment PQ = 8 cm. Consider a point R in its interior, such that PR = 5 cm.
NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry 11
Clearly, PR is a part of the line segment PQ and R lies in its interior. So, PR is smaller than PQ.
Hence, the whole is greater than its part and this is true for anything in any part of the world.
Note: This question is not about the fifth postulate.

We hope the NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry help you. If you have any query regarding NCERT Solutions for Class 9 Maths Chapter 5 Introduction to Euclid’s Geometry, drop a comment below and we will get back to you at the earliest.

Primary Sidebar

NCERT Exemplar problems With Solutions CBSE Previous Year Questions with Solutoins CBSE Sample Papers

Recent Posts

  • Letter to The Editor Class 12 CBSE Format, Samples and Examples
  • Speech Writing Format CBSE Class 11 Examples, Samples, Topics
  • Report Writing Class 12 Format, Examples, Topics, Samples
  • Decimals
  • CBSE Class 12 English Letter Writing – Letters Of Application for Jobs
  • NCERT Exemplar Problems Class 7 Maths – Exponents and Powers
  • NCERT Exemplar Class 7 Maths Practical Geometry Symmetry and Visualising Solid Shapes
  • NCERT Exemplar Class 7 Maths Algebraic Expression
  • NCERT Solutions for Class 11 Maths Chapter 8 Binomial Theorem Ex 8.2
  • NCERT Exemplar Problems Class 7 Maths – Perimeter and Area
  • NEET Physics Chapter Wise Mock Test – General properties of matter
  • ML Aggarwal Class 10 Solutions for ICSE Maths Chapter 6 Factorization MCQS
  • Division of a Polynomial by a Monomial
  • Multiplication-Decimal Numbers
  • Proper, Improper and Mixed fractions

Footer

Maths NCERT Solutions

NCERT Solutions for Class 12 Maths
NCERT Solutions for Class 11 Maths
NCERT Solutions for Class 10 Maths
NCERT Solutions for Class 9 Maths
NCERT Solutions for Class 8 Maths
NCERT Solutions for Class 7 Maths
NCERT Solutions for Class 6 Maths

SCIENCE NCERT SOLUTIONS

NCERT Solutions for Class 12 Physics
NCERT Solutions for Class 12 Chemistry
NCERT Solutions for Class 11 Physics
NCERT Solutions for Class 11 Chemistry
NCERT Solutions for Class 10 Science
NCERT Solutions for Class 9 Science
NCERT Solutions for Class 7 Science
MCQ Questions NCERT Solutions
CBSE Sample Papers
cbse ncert
NCERT Exemplar Solutions LCM and GCF Calculator
TS Grewal Accountancy Class 12 Solutions
TS Grewal Accountancy Class 11 Solutions