**NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Ex 4.1**

**Exercise 4.1**

Ex 4.1 Class 6 Maths Question 1.

Use the figure to name:

(a) Five points

(b) A line

(c) Four rays

(d) Five line segments

Solution:

(a) Five points are: O, B, C, E and D

Ex 4.1 Class 6 Maths Question 6.

Consider the following figure of line MN. Say whether following statements are true or false in context of the given figure.

Solution:

(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 Ex 4.2**

**Exercise 4.2**

Ex 4.2 Class 6 Maths Question 1.

Classify the following curves as (i) open or (ii) closed.

Ex 4.2 Class 6 Maths Question 2.

Draw rough diagrams to illustrate the following:

(a) Open curve

(b) Closed curve

Solution:

**NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Ex 4.3**

**Exercise 4.3**

Ex 4.3 Class 6 Maths Question 1.

Name the angles in the given figure.

(a) In the interior of ∠DOE

(b) In the exterior of ∠EOF

(c) On ∠EOF

Solution:

(a) A is the point in the interior ∠DOE.

(b) C is the point in the exterior ∠EOF.

(c) B is the point on ∠EOF.

Ex 4.3 Class 6 Maths Question 3.

Draw rough diagrams of two angles such that they have

(а) one point in common.

(b) two points in common.

(c) three points in common.

(d) four points in common.

(e) One ray in common.

Solution:

(a) In figure (a), O is the common point of ∠AOB and ∠COB.

**NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Ex 4.4**

**Exercise 4.4**

Ex 4.4 Class 6 Maths Question 1.

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?

Solution:

Triangle ABC is the given triangle.

P is in the interior of ∆ABC.

Q is in the exterior of ∆ABC.

A is neither in the exterior nor in the interior.

Ex 4.4 Class 6 Maths Question 2.

(a) Identify three triangles in the figure.

(6) Write the names of seven angles.

(c) Write the names of six line segments.

(d) Which two triangles have ∠B as common?

Solution:

(a) Three triangles are: ∆ABC, ∆ABD and ∆ADC.

(b) (i) ∠ABC

(ii) ∠ADB

(iii) ∠BAD

(iv) ∠ADC

(v) ∠ACD

(vi) ∠DAC

(vii) ∠BAC.

(c) AB¯¯¯¯¯¯¯¯ , BD¯¯¯¯¯¯¯¯ , AD¯¯¯¯¯¯¯¯ , AC¯¯¯¯¯¯¯¯ , DC¯¯¯¯¯¯¯¯ , BC¯¯¯¯¯¯¯¯

(c) ∆ABC and ∆ABD have ∠B as common.

**NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Ex 4.5**

**Exercise 4.5**

Ex 4.5 Class 6 Maths Question 1.

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?

Solution:

**NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Ex 4.6**

**Exercise 4.6**

Ex 4.6 Class 6 Maths Question 1.

From the figure, identify:

(a) the centre of circle

(b) three radii

(c) a diameter

(d) a chord

(e) two points in the interior

Ex 4.6 Class 6 Maths Question 2.

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

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

Solution:

(a) Yes, every diameter is the longest chord of a circle.

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

Draw any circle and mark

(a) its centre

(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.

Solution:

In the given circle,

Say ‘true’ or ‘false’.

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

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

Solution:

(a) True

(b) True