ncert-solutions-class-7-maths-ch-14-symmetry

 NCERT Solutions for Class 7 Maths Chapter 14 Symmetry

NCERT solutions for class 7 maths chapter 14 symmetry exercise 14.1
Question:1 .(a) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry is as shown :

Question:1.(b) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry is as shown :

Question: 1.(c) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry is as shown :

Question: 1.(d) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry is as shown :

Question: 1 .(e) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry is as shown :

Question: 1 (f) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry is as shown :

Question: 1 (g) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry is as shown :

Question: 1( h) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry are as shown :

Question: 1(i) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry is as shown :

Question: 1(j) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry is as shown :

Question: 1.(k) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry is as shown :

Question:1.(l) Copy the figures with punched holes and find the axes of symmetry for the following:

Answer:

The axes of symmetry is as shown :

Question: 2 Given the line(s) of symmetry, find the other hole(s):

Answer:

The other holes from the symmetry are as shown :

Question:3 In the following figures, the mirror line (i.e., the line of symmetry) is given as a dotted line. Complete each figure performing reflection in the dotted (mirror) line. (You might perhaps place a mirror along the dotted line and look into the mirror for the image). Are you able to recall the name of the figure you complete?

Answer:

The complete figures are as shown :

(a) square (b)triangle (c)rhombus

(d)circle (e) pentagon (f) octagon

Question: 4 The following figures have more than one line of symmetry. Such figures are said to have multiple lines of symmetry.

Identify multiple lines of symmetry, if any, in each of the following figures:

Answer:

The lines of symmetry of figures are:

(a)There are 3 lines of symmetry. Thus, it has multiple lines of symmetry.

(b) There are 2 lines of symmetry. Thus, it has multiple lines of symmetry.

(c)There are 3 lines of symmetry. Thus, it has multiple lines of symmetry.

(d)There are 2 lines of symmetry. Thus, it has multiple lines of symmetry.

(e)There are 4 lines of symmetry. Thus, it has multiple lines of symmetry.

(f)There is 1 line of symmetry.

(g)There are 4 lines of symmetry. Thus, it has multiple lines of symmetry.

(h)There are 6 lines of symmetry. Thus, it has multiple lines of symmetry.

Question: 5 Copy the figure given here. Take any one diagonal as a line of symmetry and shade a few more squares to make the figure symmetric about a diagonal. Is there more than one way to do that? Will the figure be symmetric about both the diagonals?

Answer:

The figure with symmetry may be as shown :

Yes,there more than one way .

Yes,the figure be symmetric about both the diagonals

Question: 6 Copy the diagram and complete each shape to be symmetric about the mirror line(s):

Answer:

The complete shape symmetric about the mirror line(s) are :

Question: 7 State the number of lines of symmetry for the following figures:

(a) An equilateral triangle (b) An isosceles triangle (c) A scalene triangle
(d) A square (e) A rectangle (f) A rhombus
(g) A parallelogram (h) A quadrilateral (i) A regular hexagon
(j) A circle

Answer:

(a) An equilateral triangle

The number of lines of symmetry = 3

(b) An isosceles triangle

The number of lines of symmetry = 1

(c) A scalene triangle

The number of lines of symmetry = 0

(d) A square

The number of lines of symmetry = 4

(e) A rectangle

The number of lines of symmetry = 2

(f) A rhombus

The number of lines of symmetry = 2

(g) A parallelogram

The number of lines of symmetry = 0

(h) A quadrilateral

The number of lines of symmetry = 0

(i) A regular hexagon

The number of lines of symmetry = 6

(j) A circle

The number of lines of symmetry = infinite

Question: 8 What letters of the English alphabet have reflectional symmetry (i.e., symmetry related to mirror reflection) about?

(a) a vertical mirror

(b) a horizontal mirror

(c) both horizontal and vertical mirrors

Answer:

(a) a vertical mirror : A,H,I,M,O,T,U,V,W,X and Y

(b) horizontal mirror : B,C,D,E,H,I,O and X

(c) both horizontal and vertical mirrors : H,I,O and X.

Question: 9 Give three examples of shapes with no line of symmetry.

Answer:

The three examples of shapes with no line of symmetry are :

1. Quadrilateral

2. Scalene triangle

3.Parallelogram

Question:1 0.(a) What other name can you give to the line of symmetry of

an isosceles triangle?

Answer:

The line of symmetry of an isosceles triangle is median or altitude.

Question: 10.(b) What other name can you give to the line of symmetry of

a circle?

Answer:

The other name we can give to the line of symmetry of a circle is the diameter.

NCERT solutions for class 7 maths chapter 14 symmetry topic 14.3

Question: 1.(a) Can you now tell the order of the rotational symmetry for an equilateral triangle?

Answer:

An equilateral triangle has rotational symmetry at  angle. The order of the rotational symmetry for an equilateral triangle is 3.

Question: 1.(b) How many positions are there at which the triangle looks exactly the same, when rotated about its centre by 120°?

Answer:

All the triangles look same when rotated by  . Thus, there are 4 positions at which the triangle looks exactly the same when rotated about its centre by 120°.

Question:2 Which of the following shapes (Fig 14.15) have rotational symmetry about the marked point.

Answer:

Among the above-given shapes, (i),(ii) and (iv) have rotational symmetry about the marked point.

NCERT solutions for class 7 maths chapter 14 symmetry exercise 14.2

Question: 1 Which of the following figures have rotational symmetry of order more than 1:

Answer:

Among the above-given shapes, (a),(b), (d),(e) and (f) have more than one rotational symmetry.

This is because, in these figures, a complete turn, more than 1 number of times, an object look exactly the same.

Question: 2 Give the order of rotational symmetry for each figure:

Answer:

(a) The given figure has rotational symmetry about  so it has ordered as 2.

(b) The given figure has rotational symmetry about  so it has ordered as 2.

(c) The given figure has rotational symmetry about  so it has ordered as 3.

(d) The given figure has rotational symmetry about  so it has ordered as 4.

(e) The given figure has rotational symmetry about <img alt="90 \degree" height="13"

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(f) The given figure has rotational symmetry about  so it has ordered as 5.

(g) The given figure has rotational symmetry about  so it has ordered as 6.

(h) The given figure has rotational symmetry about  so it has ordered as 3.

NCERT solutions for class 7 maths chapter 14 symmetry exercise 14.3

Question: 1 Name any two figures that have both line symmetry and rotational symmetry.

Answer:

The two figures that have both line symmetry and rotational symmetry are :

(i) Equilateral triangle

(ii) Regular hexagon

Question:2(i) Draw, wherever possible, a rough sketch of

a triangle with both line and rotational symmetries of order more than 1.

Answer:

Line of symmetry as shown below :

The rotational symmetry as shown below :

Question: 2(ii) Draw, wherever possible, a rough sketch of

a triangle with only line symmetry and no rotational symmetry of order more than 1.

Answer:

A triangle with only line symmetry and no rotational symmetry of order more than 1 is isosceles triangle.

Question:2(iii) Draw, wherever possible, a rough sketch of

a quadrilateral with a rotational symmetry of order more than 1 but not a line symmetry.

Answer:

A quadrilateral with a rotational symmetry of order more than 1 but not a line symmetry is parallelogram.

Question: 2(iv) Draw, wherever possible, a rough sketch of

a quadrilateral with line symmetry but not a rotational symmetry of order more than 1.

Answer:

A quadrilateral with line symmetry but not a rotational symmetry of order more than 1 is kite.

Question:3 If a figure has two or more lines of symmetry, should it have rotational symmetry of order more than 1?

Answer:

Yes. If a figure has two or more lines of symmetry,than it should have rotational symmetry of order more than 1.

Question: 4 Fill in the blanks:

Shape	Centre of Rotation	Order of Rotation	Angle of Rotation
Square
Rectangle
Rhombus
Equilateral Triangle
Regular Hexagon
Circle
Semi-circle

Answer:

The given table is completed as shown:

Shape	Centre of Rotation	Order of Rotation	Angle of Rotation
Square	intersection point of digonals.	4
Rectangle	Intersection point of digonals.	2
Rhombus	Intersection point of digonals.	2
Equilateral Triangle	Intersection point of medians.	3
Regular Hexagon	Intersection point of digonals.	6
Circle	centre of circle	infinite	any angle
Semi-circle	centre of circle	1

Question: 5 Name the quadrilaterals which have both line and rotational symmetry of order more than 1.

Answer:

The quadrilaterals which have both line and rotational symmetry of order more than 1 are :

1. Rectangle

2. Square

3. Rhombus

Question: 6 After rotating by  about a centre, a figure looks exactly the same as its original position. At what other angles will this happen for the figure?

Answer:

After rotating by  about a centre, a figure looks exactly the same as its original position, then it will look symmetrical on rotating by  All angles are multiples of  .

Question: 7 Can we have a rotational symmetry of order more than 1 whose angle of rotation is:

Answer:

We can observe that the angle of rotation is the factor of  ,then it will have rotational symmetry of order more than 1.

(i)  is a factor of  so the figure having its angle of rotation as  will have rotational symmetry of order more than 1.

(ii)  is not a factor of  so the figure having its angle of rotation as  will not have rotational symmetry of order more than 1.

Responsive Table

Chapter No.Chapter Name

Chapter 1	NCERT solutions for class 7 maths chapter 1 Integers
Chapter 2	NCERT solutions for class 7 maths chapter 2 Fractions and Decimals
Chapter 3	NCERT solutions for class 7 maths chapter 3 Data Handling
Chapter 4	NCERT solutions for class 7 maths chapter 4 Simple Equations
Chapter 5	NCERT solutions for class 7 maths chapter 5 Lines and Angles
Chapter 6	NCERT solutions for class 7 maths chapter 6 The Triangle and its Properties
Chapter 7	NCERT solutions for class 7 maths chapter 7 Congruence of Triangles
Chapter 8	NCERT solutions for class 7 maths chapter 8 comparing quantities
Chapter 9	NCERT solutions for class 7 maths chapter 9 Rational Numbers
Chapter 10	NCERT solutions for class 7 maths chapter 10 Practical Geometry
Chapter 11	NCERT solutions for class 7 maths chapter 11 Perimeter and Area
Chapter 12	NCERT solutions for class 7 maths chapter 12 Algebraic Expressions
Chapter 13	NCERT solutions for class 7 maths chapter 13 Exponents and Powers
Chapter 14	NCERT solutions for class 7 maths chapter 14 Symmetry
Chapter 15	NCERT solutions for class 7 maths chapter 15 visualising-solid-shapes

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 NCERT Solutions for Class 7 Maths Chapter 14 Symmetry NCERT solutions for class 7 maths chapter 14 symmetry exercise 14.1 Question:1 .(a)...