NCERT Solutions for Class 7 Maths Exercise – 14.3

NCERT Solution for Class 7th Maths Exercise – 14.3 Chapter – 14 Symmetry

 

 

Q1. Name any two figures that have both line symmetry and rotational symmetry.

Solution:-

 

Equilateral triangle and circle.

 

Q2. Draw wherever possible , a rough sketch of

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

Solution:-

 

A triangle with both line and rotational symmetries of order more than 1 is an equilateral triangle.

 

Line Symmetry

 

 

Rotational Symmetry

 

 

 

 

 

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

Solution:-

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

isosceles triangle.

 

 

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

Solution:-

 

A triangle with only time symmetry and no rational symmetry of order more than 1 is isosceles triangles .

 

 

 

 

 

 

 

III. A Quadrilateral with a rational symmetry of order more than 1 but not a line symmetry .

Solution:-

 

A quadrilateral with a rotational symmetry of order  more than 1. but not a line symmetry is not possible to draw. Because , a quadrilateral with a line symmetry may have rotational symmetry of order one but not more than one.

 

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

Solution:-

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

 

 

Q3. If a figure has two or more lines of symmetry should it have rotational symmetry of order more than 1?

Solution:-

 

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

 

Q4. Fill in the blanks:

Shape Centre of rotation Order of rotation Angle of rotation
Square      
Rectangle      
Rhombus      
Equilateral triangle      
Regular Hexagon      
Circle      
Semi – Circle      

 

Solution:-

Shape Centre of rotation Order of rotation Angle of rotation
Square Intersecting point of diagonals 4 90o
Rectangle Intersecting point of diagonal 2 180o
rhombus Intersecting point of diagonals 2 180o
Equilateral triangle Intersecting point of medians 3 120o
Regular hexagon Intersecting point of diagonals 6 60o
circle centre Infinite Every angle
Semi-circle Mid – point of diameter 1 360o

 

 

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

Solution:-

The quadrilateral which have both line and rational symmetry of order more than 1 is square .

Line symmetry:

 

 

Rotational symmetry :

 

Q-6 After rotating by 60o about a centre, a figure looks exactly the same as its original position .  at what other angles will this happen for the figure ?

Solution:-

The other angles are ,120o, 180o , 240o, 300o, 360o

So, the figure is said to have rational symmetry about same angles as the first one . hence , the figure will look exactly the same when rotated by 60o from the last position .

 

 

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

 

  1. 45o

Solution:-

Yes . we can have a rotational symmetry of order more than 1 whose angle of rotation is 45o .

 

  1. 17

Solution:-

No.  we cannot have a rotational symmetry of order more than 1 whose angle of rotation is 17o.

NCERT Solutions for class 7 Science Chapter –

 

NCERT Solution for Class 7th Maths Exercise – 14.3 Chapter – 14 Symmetry     Q1. Name any two figures that…