CBSE students can refer to NCERT Solutions for Class 7 Maths Chapter 14 Symmetry Ex 14.3 Textbook Questions and Answers are provided by experts in order to help students secure good marks in exams.
Class 7 Maths NCERT Solutions Chapter 14 Symmetry Ex 14.3
Question 1.
Name any two figures that have both line symmetry and rotational symmetry.
Solution:
- Circle
- Equilateral triangle
Question 2.
Draw, wherever possible, a rough sketch of
(i) a triangle with both line and rotational symmetries of order more than 1.
Solution:
Three lines of symmetry
Also, an equilateral triangle has rotational symmetry of order 3 as shown below:
(ii) a triangle with only line symmetry and no rotational symmetry of order more than 1.
Solution:
One line of symmetry but no rotational symmetry of order more than 1.
(iii) a quadrilateral with rotational symmetry of order more than 1 but not a line symmetry.
Solution:
No line of symmetry but have rotational symmetry of order more than 1.
(iv) a quadrilateral with line symmetry but not a rotational symmetry or order more than 1.
Solution:
One line of symmetry but no rotational symmetry of order more than 1.
Question 3.
If a figure has two or more lines of symmetry, should it have rotational symmetry of order more than 1?
Solution:
When a figure has two or more lines of symmetry, then the figure 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 | |||
Semicircle |
Solution:
Shape | Centre of Rotation | Order of Rotation | Angle of Rotation |
Square | Yes | 4 | 90° |
Rectangle | Yes | 4 | 90° |
Rhombus | Yes | 4 | 90° |
Equilateral Triangle | Yes | 3 | 120° |
Regular Hexagon | Yes | 6 | 60° |
Circle | Yes | Infinite | Any angle |
Semicircle | Yes | 4 | 90° |
Question 5.
Name the quadrilaterals which have both line and rotational symmetry of order more than 1.
Solution:
- Square
- Rectangle
Question 6.
After rotating by 60° about a center, 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 120°, 180°, 240°, 300°, 360°.
Question 7.
Can we have rotational symmetry of order more than 1 whose angle of rotation is
(i) 45°?
Solution:
Yes
(ii) 17°?
Solution:
No