NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.1 (Rationalised Contents)
NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.1 are the part of NCERT Solutions for Class 7 Maths (Rationalised Contents). Here you
can find the NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.1.
- NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.1
- NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.2
- NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.3
Ex 12.1 Class 7 Maths Question 1.
Copy the figures with punched holes and find the axis of symmetry for the following:
Solution:
The axis of symmetry is drawn in the following figures.
Ex 12.1 Class 7 Maths Question 2.
Give the line(s) of symmetry, find the other hole(s):
Solution:
Ex 12.1 Class 7 Maths Question 3.
In the following figures, the mirror line (i.e., the line of symmetry) is given as 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?
Solution:
The following are the completed figures.
Ex 12.1 Class 7 Maths 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:
Solution:
Here, figures (b), (d), (e), (g) and (h) have multiple lines of symmetry.
Ex 12.1 Class 7 Maths 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?
Solution:
Let us take a diagonal as the line of symmetry and shade the square to make the figure symmetric.
Yes, there are more than one line of symmetry, i.e. BD, EF and GH.
Yes, the figure is symmetric about both the diagonals.
Ex 12.1 Class 7 Maths Question 6.
Copy the diagram and complete each shape to be symmetric about the mirror line(s).
Solution:
Ex 12.1 Class 7 Maths Question 7.
State the number of lines of symmetry for the following figures:
(а) 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
Solution:
Figure | Number of lines of symmetry |
(a) An equilateral triangle | 3 |
(6) An isosceles triangle | 1 |
(c) A scalene triangle | 0 |
(d) A square | 4 |
(e) A rectangle | 2 |
(f) A rhombus | 2 |
(g) A parallelogram | 0 |
(h) A quadrilateral | 0 |
(i) A regular hexagon | 6 |
(j) A circle | Infinite |
Ex 12.1 Class 7 Maths Question 8.
What letters of the English alphabet have reflectional symmetry (i.e., symmetry related to mirror reflection) about
(а) a vertical mirror
(b) a horizontal mirror
(c) both horizontal and vertical mirrors.
Solution:
(a) Alphabets that have reflection symmetry about a vertical mirror are:
A, H, I, M, O, T, U, V, W, X, Y
(b) Alphabets that have reflection symmetry about a horizontal mirror are:
B, C, D, E, H, I, K, O, X
(c) Alphabets that have reflection symmetry about both horizontal and vertical mirrors are:
H, I, O, X
Ex 12.1 Class 7 Maths Question 9.
Give three examples of shapes with no line of symmetry.
Solution:
1. A scalene triangle
2. A parallelogram
3. A quadrilateral
The above shapes have no line of symmetry.
Ex 12.1 Class 7 Maths Question 10.
What other name can you give to the line of symmetry of
(a) an isosceles triangle?
(b) a circle?
Solution:
(a) Median or Altitude
(b) Diameter
Related Links:
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NCERT Solutions for Maths Class 10
NCERT Solutions for Maths Class 11