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NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas

Edited By Ramraj Saini | Updated on Nov 29, 2023 05:17 PM IST

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas are discussed here. These NCERT solutions are prepared by subjects matter expert at careers360 keeping in my the latest CBSE syllabus 2023. This NCERT Class 6 solution for chapter 4 will introduce figures like- triangle, quadrilaterals, circles, polygon, regular polygon, etc, which you often observe in your day-to-day lives. NCERT solutions for Class 6 Maths chapter 4 Basic Geometrical Ideas covers the solutions of all these kinds of shapes. In this particular chapter of NCERT, you will learn more about the shapes around us. NCERT Class 6 solution for chapter 4 Basic Geometrical Ideas will help in creating a foundation of geometry for the upcoming classes.

Before going through the Class 6 Maths NCERT solutions, check the NCERT Syllabus for Class 6 Maths to get the basic outline of the topics. CBSE NCERT solutions for Class 6 Maths chapter 4 is created to help you when you are while you. This chapter is having a total of 23 questions in 6 exercises. NCERT solutions for Class 6 Maths chapter 4 Basic Geometrical Ideas are covering all the questions' solutions given in the NCERT Books for Class 6 Maths. Along with Class 6 NCERT solution for Maths chapter 4, you can take a look at.

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas - Important Formula

  1. Line segments are the shortest distance between two points.
  2. They are represented by a straight line connecting two specific points, denoted as AB
  3. When two distinct lines meet at a common point, they are called intersecting lines.
  4. Parallel lines are lines that will never intersect each other.
  5. A polygon is a closed figure made up of different line segments.
  6. Any two sides of a polygon that share a common endpoint are called adjacent sides.
  7. The point where a pair of sides meet in a polygon is called a vertex.
  8. Vertices that are located on the same sides of a polygon are called adjacent vertices.
  9. A diagonal is a line segment that connects the endpoints of two non-adjacent vertices in a polygon.
  10. A quadrilateral is a polygon with four sides.
  11. In a quadrilateral ABCD, sides AB and CD are pairs of opposite sides.
  12. Similarly, sides BC and AD are pairs of opposite sides.
  13. In a quadrilateral ABCD, angles ABC and CDA are pairs of opposite angles.
  14. Similarly, angles BCD and DAB are pairs of opposite angles.
  15. Angle BCD is adjacent to angles ABC and CDA.
  16. Similar relations hold for the other three angles in the quadrilateral.

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas - Important Points

Point: A point is a fundamental geometric concept that represents a location in space. It has no size, shape, or dimensions and is usually denoted by a capital letter.

Line Segment: A line segment is a part of a line that connects two distinct points. It is the shortest distance between the two points and is represented by the two endpoints denoted as AB, where A and B are the endpoints.

Line: A line is formed by extending a line segment infinitely in both directions. It has no endpoints and continues indefinitely. A line is denoted by using the two endpoints of a line segment, such as AB, or sometimes represented by a single small letter like 'l'.

Intersecting Lines: When two distinct lines meet or cross at a single point, they are called intersecting lines. The point at which they intersect is known as the point of intersection.

Parallel Lines: Two lines in a plane are said to be parallel if they do not intersect, even when extended indefinitely. Parallel lines never meet and remain equidistant from each other at all points.

Ray: A ray is a portion of a line that starts from a point (called the endpoint) and extends infinitely in one direction. It has only one endpoint but goes on indefinitely in the other direction.

Curve: In geometry, a curve refers to any continuous and smooth line, whether straight or non-straight, that can be drawn without lifting the pencil. In this context, a line is also considered a curve.

Simple Curve: A simple curve is a curve that does not intersect or cross itself. It is a smooth and continuous curve without any self-intersections.

Closed Curve: A closed curve is a curve whose ends are joined, forming a complete loop or shape without any openings. It creates a boundary that encloses a region. In contrast, an open curve does not have its ends connected.

Polygon: A polygon is a simple closed curve made up of line segments. It is a two-dimensional geometric figure with straight sides. The properties of a polygon include:

(i) Sides: The line segments that form the polygon are called sides.

(ii) Adjacent Sides: Any two sides that share a common endpoint are called adjacent sides.

(iii) Vertex: The meeting point of two sides is called a vertex (plural: vertices).

(iv) Adjacent Vertices: The endpoints of the same side are known as adjacent vertices.

(v) Diagonal: The line segment that joins any two non-adjacent vertices of a polygon is called a diagonal.

Angle: An angle is formed by two rays that share a common initial point. The rays are referred to as the sides of the angle, and the common initial point is called the vertex of the angle. The angle is denoted by the three-letter notation, where the vertex is mentioned in the middle (e.g., ∠AOB or ∠BOA).

An angle divides the space around it into three regions:

Angle Itself: The actual measurement between the two rays that form the angle.

Interior of the Angle: The region enclosed by the angle's sides.

Exterior of the Angle: The region outside the angle but within the plane.

Free download NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas PDF for CBSE Exam

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas

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NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas (Intext Questions and Exercise)

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Topic: Line Segment

Q1 Name the line segments in the figure. Is A, the endpoint of each line segment?

1643036777918

Answer: The line segments in the figure are BA and AC.

A is one of the endpoints of both BA and AC.

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Topic: Ray

Q1 Name the rays given in this picture.

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Answer: The rays given in this picture are TA and TB.

Q2 Is T a starting point of each of these rays?

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Answer: Yes. T is the starting point of each these rays.

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Exercise: 4.1

Q1 Use the figure to name :

(a) Five points

(b) A line

(c) Four rays

(d) Five line segments

1643036887152

Answer: (a) D, E, O, B and C

(b) DB or BD

(c) \vec{OE}, \vec{OD},\vec{OB}\ and\ \vec{OC}

(d) \bar{OE}, \bar{OD},\bar{OB},\bar{DE}\ and\ \bar{EB}


Q2 Name the line given in all possible (twelve) ways, choosing only two letters at a time from the four given.

1643036915673

Answer: The given line can be named in the following 12 ways.

AB, BA, AC, CA, AD, DA, BC, CB, BD, DB, CD and DC.

Q3 Use the figure to name :

(a) Line containing point E.

(b) Line passing through A.

(c) Line on which O lies

(d) Two pairs of intersecting lines.

1643036946307

Answer: (a) Line containing point E is DE or FE.

(b) Line passing through A is AE.

(c) Line on which O lies is OC.

(d) Two pairs of inter secting lines are

(i) CO and AE

(ii) AE and EF

Q4 How many lines can pass through

(a) one given point?

(b) two given points?

Answer: (a) Infinite lines can pass through a given point.

(b) Only one line can pass through two given points.

Q6 Consider the following figure of line \overline{MN} . Say whether following statements are true or false in context of the given figure.

(a) Q, M, O, N, P are points on the line \overline{MN} .

(b) M, O, N are points on a line segment \overline{MN} .

(c) M and N are end points of line segment \overline{MN} .

(d) O and N are end points of line segment \overline{OP} .

(e) M is one of the end points of line segment \overline{QO} .

(f) M is point on ray \overrightarrow{OP} .

(g) Ray \overrightarrow{OP} is different from ray \overrightarrow{QP} .

(h) Ray \overrightarrow{OP} is same as ray \overrightarrow{OM} .

(i) Ray \overline{OM} is not opposite to ray \overline{OP} .

(j) O is not an initial point of \overline{OP} .

(k) N is the initial point of \overline{NP} and \overline{NM} .

1643037103732


Answer: (a) True

(b) True

(c) True

(d) False

(e) False

(f) False

(g) True

(h) False

(i) False

(j) False

(k) True

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Exercise: 4.2

Q1 Classify the following curves as (i) Open or (ii) Closed

sunny

Answer: (a) Open

(b) Closed

(c) Open

(d) Closed

(e) Closed

Q4 Consider the given figure and answer the questions :

(a) Is it a curve? (b) Is it closed?

1643037232833

Answer: (a) Yes it is a curve.

(b) Yes it is closed.

Q5 Illustrate, if possible, each one of the following with a rough diagram:

(a) A closed curve that is not a polygon.

(b) An open curve made up entirely of line segments.

(c) A polygon with two sides.

Answer: (a) A closed curve that is not a polygon is possible.

e.g an ellipse or a circle

1643037261692

(b) An open curve made up entirely of line segments

1643037273290

(c) A polygon with two sides is not possible since by definition polygons are closed figures which require at least three line segments to be made.

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Exercise: 4.3

Q1 Name the angles in the given figure.

1643037299610


Answer: The angles in the given figure are \angle ABC,\angle BCD,\angle CDA\ and\ \angle DAB


Q2 In the given diagram, name the point(s)

(a) In the interior of \angle DOE

(b) In the exterior of \angle EOF

(c) On \angle EOF

1643037332373

Answer: (a) Point A

(b) Points C, A and D

(c) Points E, B, O and F

Q3 Draw rough diagrams of two angles such that they have

(a) One point in common.

(b) Two points in common.

(c) Three points in common.

(d) Four points in common.

(e) One ray in common.

Answer: (a) \angle AOB and \angle COD have point O in common.

1643037368909

(b) \angle AOB and \angle BOC have points O and B in common.

1643037379630

(c) \angle AOB and \angle BOC have points O, D and B in common.

1643037391312

(d) \angle AOB and \angle BOC have points O, D, E and B in common.

1643037403217

(e) \angle AOB and \angle BOC have ray \vec{OB} in common

1643037413965

Note: You will find the solutions at many sites saying that the angles required in (c) and (d) is not possible but that will be the case only if it is mentioned that the common points have to be on different rays.

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Exercise: 4.4

Q1 Draw a rough sketch of a triangle ABC. Mark a point P in its interior and a point Q in its exterior. Is the point A in its exterior or in its interior?

Answer: The sketch of the required triangle is as follows

1643037443316

Point A is neither in the interior or the exterior of the triangle ABC. It is a vertex.

Q2 (a) Identify three triangles in the figure.

(b) Write the names of seven angles.

(c) Write the names of six line segments.

(d) Which two triangles have \angle B as common?

1643037496179

Answer: (a) Three triangles in the given figure are \Delta ABD , \Delta ACD and \Delta ABC .

(b) Seven angles in the given figure are \angle ABD , \angle BDA , \angle DAB , \angle ADC , \angle DCA , \angle CAD and \angle BAC .

(c) Six line segments in the given figure are AB, BC, CA, AD, BD and DC.

(d) \Delta ABD and \Delta ABC have \angle B as common.


NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Exercise: 4.5

Q1 Draw a rough sketch of a quadrilateral PQRS. Draw its diagonals. Name them. Is the meeting point of the diagonals in the interior or exterior of the quadrilateral?

Answer: Sketch of the required quadrilateral PQRS is as follows.

1643037524720

Its diagonals are PR and QS which meet at the point O. The meeting point of the diagonals O is in the interior of the quadrilateral.

Q2 Draw a rough sketch of a quadrilateral KLMN. State,

(a) two pairs of opposite sides,

(b) two pairs of opposite angles,

(c) two pairs of adjacent sides,

(d) two pairs of adjacent angles.

Answer: The following is the sketch of a quadrilateral KLMN

1643037554060

(a) Two pairs of opposite sides are

(i) KL and MN.

(ii) LM and NK

(b) Two pairs of opposite angles are

(i) \angle KLM and \angle MNK

(ii) \angle LMN and \angle NKL

(c) Two pairs of adjacent sides are

(i) KL and LM

(ii) LM and MN

(d) Two pairs of adjacent angles are

(i) \angle KLM and \angle LMN

(ii) \angle NKL and \angle MNK

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Exercise: 4.6

Q1 From the figure, identify :

(a) the center of the circle

(b) three radii

(c) a diameter

(d) a chord

(e) two points in the interior

(f) a point in the exterior

(g) a sector

(h) a segment

1643037588485

Answer: (a) O is the centre of the circle.

(b) OA, OB and OC are three radii of the circle.

(c) AC is a diameter of the circle.

(d) ED is a chord of the circle.

(e) Points O and P are in the interior of the circle.

(f) Point Q is a point in the exterior of the circle.

(g) The shaded region OAB is a sector of the circle.

(h) The shaded region EDE is a segment of the circle.

Q2 (a) Is every diameter of a circle also a chord?

(b) Is every chord of a circle also a diameter?

Answer: (a) Yes, every diameter of a circle is also a chord.

(b) No, not every chord of a circle is a diameter.

Q3 Draw any circle and mark

(a) it's center

(b) a radius

(c) a diameter

(d) a sector

(e) a segment

(f) a point in its interior

(g) a point in its exterior

(h) an arc

Answer:

1643037625824

In the above-drawn circle

(a) O is the center of the circle.

(b) OR is a radius of the circle.

(c) PQ is a diameter of the circle.

(d) Shaded region OSQ is a sector of the circle.

(e) Shaded region ABC is a segment of the circle.

(f) K is a point in the interior of the circle.

(g) L is a point in the exterior of the circle.

(h) UV is an arc of the circle.

Q4 Say true or false :

(a) Two diameters of a circle will necessarily intersect.

(b) The center of a circle is always in its interior.

Answer: (a)Two diameters of a circle will necessarily intersect - True.

(b) The center of a circle is always in its interior- True.

Key Features Of Basic Geometrical Ideas Class 6 Maths Chapter 4

Comprehensive Coverage: The maths class 6 chapter 4 provides a comprehensive coverage of basic geometric concepts, ensuring a thorough understanding of fundamental ideas in geometry.

Structured Learning: The NCERT solutions for class 6 maths chapter 4 is organized in a structured manner, introducing concepts gradually and building upon previous knowledge. This allows for a step-by-step understanding of geometric ideas.

Clear Explanations: The chapter offers clear explanations of geometric terms and concepts, making it easier for students to grasp and apply them.

Also Check

NCERT Books and NCERT Syllabus

NCERT Solutions for Class 6 Mathematics - Chapter Wise

Chapters No.

Chapters Name

Chapter - 1

Knowing Our Numbers

Chapter - 2

Whole Numbers

Chapter - 3

Playing with Numbers

Chapter - 4

Basic Geometrical Ideas

Chapter - 5

Understanding Elementary Shapes

Chapter - 6

Integers

Chapter - 7

Fractions

Chapter - 8

Decimals

Chapter - 9

Data Handling

Chapter -10

Mensuration

Chapter -11

Algebra

Chapter -12

Ratio and Proportion

Chapter -13

Symmetry

Chapter -14

Practical Geometry

NCERT Solutions for Class 6 - Subject Wise

How to Use NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas?

  • Try to relate all the figures with the things around us.
  • Learn the concepts given related to a particular figure.
  • Take a look through some examples to understand the application of those concepts.
  • Solve the unsolved problems given in the practice exercises.
  • While solving the unsolved questions if you stuck anywhere you can take the help of NCERT Solutions for Class 6 .

Keep working hard always and happy learning!

Frequently Asked Questions (FAQs)

1. What is the meaning of Geometry according class 6 chapter 4 maths?

Geometry has a long history. The 'Geometry' is the English equivalent of the Greek word 'Geometron'.

'Geo' means Earth and the 'Metron' means Measurement. thus according to chapter 4 maths class 6 geometry studies the sizes, shapes, positions, angles, and dimensions of things.

2. What is the largest chord of a circle?

The largest chord of a circle is called the diameter. The diameter is a chord that passes through the center of the circle and divides it into two equal halves. It is the longest possible chord in a circle and its length is twice the length of the radius. In other words, the diameter is the line segment that connects two points on the circle and passes through the center.

3. Please provide the definition of a polygon as described in NCERT Solutions for class 6 chapter 4 Maths.

As per the explanation provided in basic geometrical ideas class 6 worksheet with answers, a polygon is a closed shape formed by connecting line segments. Polygons come in various types, such as triangles (consisting of 3 line segments), quadrilaterals (consisting of 4 line segments), pentagons (consisting of 5 line segments), and so on.

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A block of mass 0.50 kg is moving with a speed of 2.00 ms-1 on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is

Option 1)

0.34\; J

Option 2)

0.16\; J

Option 3)

1.00\; J

Option 4)

0.67\; J

A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1 m 1000 times.  Assume that the potential energy lost each time he lowers the mass is dissipated.  How much fat will he use up considering the work done only when the weight is lifted up ?  Fat supplies 3.8×107 J of energy per kg which is converted to mechanical energy with a 20% efficiency rate.  Take g = 9.8 ms−2 :

Option 1)

2.45×10−3 kg

Option 2)

 6.45×10−3 kg

Option 3)

 9.89×10−3 kg

Option 4)

12.89×10−3 kg

 

An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range

Option 1)

2,000 \; J - 5,000\; J

Option 2)

200 \, \, J - 500 \, \, J

Option 3)

2\times 10^{5}J-3\times 10^{5}J

Option 4)

20,000 \, \, J - 50,000 \, \, J

A particle is projected at 600   to the horizontal with a kinetic energy K. The kinetic energy at the highest point

Option 1)

K/2\,

Option 2)

\; K\;

Option 3)

zero\;

Option 4)

K/4

In the reaction,

2Al_{(s)}+6HCL_{(aq)}\rightarrow 2Al^{3+}\, _{(aq)}+6Cl^{-}\, _{(aq)}+3H_{2(g)}

Option 1)

11.2\, L\, H_{2(g)}  at STP  is produced for every mole HCL_{(aq)}  consumed

Option 2)

6L\, HCl_{(aq)}  is consumed for ever 3L\, H_{2(g)}      produced

Option 3)

33.6 L\, H_{2(g)} is produced regardless of temperature and pressure for every mole Al that reacts

Option 4)

67.2\, L\, H_{2(g)} at STP is produced for every mole Al that reacts .

How many moles of magnesium phosphate, Mg_{3}(PO_{4})_{2} will contain 0.25 mole of oxygen atoms?

Option 1)

0.02

Option 2)

3.125 × 10-2

Option 3)

1.25 × 10-2

Option 4)

2.5 × 10-2

If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will

Option 1)

decrease twice

Option 2)

increase two fold

Option 3)

remain unchanged

Option 4)

be a function of the molecular mass of the substance.

With increase of temperature, which of these changes?

Option 1)

Molality

Option 2)

Weight fraction of solute

Option 3)

Fraction of solute present in water

Option 4)

Mole fraction.

Number of atoms in 558.5 gram Fe (at. wt.of Fe = 55.85 g mol-1) is

Option 1)

twice that in 60 g carbon

Option 2)

6.023 × 1022

Option 3)

half that in 8 g He

Option 4)

558.5 × 6.023 × 1023

A pulley of radius 2 m is rotated about its axis by a force F = (20t - 5t2) newton (where t is measured in seconds) applied tangentially. If the moment of inertia of the pulley about its axis of rotation is 10 kg m2 , the number of rotations made by the pulley before its direction of motion if reversed, is

Option 1)

less than 3

Option 2)

more than 3 but less than 6

Option 3)

more than 6 but less than 9

Option 4)

more than 9

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