CBSE Class 6 Maths Symmetry HOTs

5. Scalene triangle, Parallelogram, Trapezium
6. a. Angle bisector b. Diameter
c. Diagonal
7. 3 digits - 0, 1, 8

HOTS

1. Using the digits 0 to 9, and not repeating the digits, write two three digit numbers that have a horizontal line of symmetry.
Answer: 138, 301

2. Name three Indian historical monuments that have line symmetry.
Answer: Tajmahal, Gateway of India, India Gate

CHALLENGES

1. Find the symmetries of the following figure. 

2. Find the symmetries of the following figure. 

3. Find the symmetries of the following figure. 

4. Is the figure symmetric about some axis? 

5. Find the symmetries of the following star. 

6. The following figure has both symmetries; rotational and reflectional. Find them. 

7. In the following figure, there are symmetries. Find them

8. Find the symmetries of the following figure. 

9. In a shop an item was priced, in rupees, a 4-digit integer. The display was digital (like in a digital clock). At an opportune moment the buyer turns the tag upside down. He gets a price ₹ 1626 less.
What was the original price? (Hint: Rotational symmetry of digits in a digital display.)

10. Take any palindrome: 12321. This also has symmetry, but not visual symmetry. What symmetry it has?

SUMMARY 

1. If we draw a line in the middle of a figure through its centre and the left side of the figure exactly overlaps its right side, then, the figure is called a symmetric figure and the line is called the line of symmetry.

2. For a figure, there may be no line of symmetry, one line of symmetry, two lines of symmetry or multiple lines of symmetry.

3. When an object is seen in a mirror, the image obtained on the other side of the mirror is called its reflection.

4. The object and its image are symmetrical with reference to the mirror line.

ERRORANALYSIS

1. Students generally make mistakes in identifying line of symmetry for a parallelogram and alphabets like Z, S, N or of regular figures.

2. Some students are not able to imagine the reflection of shapes or alphabets.

ACTIVITY

Making symmetrical figures

1. Ink-Blot Devils
Take a sheet of paper. Fold it in half. Spill few drops of coloured ink on one half side.
Now press the halves together on a flat surface and open it. The resulting figure is symmetrical and the line of fold (shown dotted) is the line of symmetry. 

2. Cutting a Design
Fold a piece of paper and cut out a shape based on the folded line. On unfolding the paper, a design is obtained. Observe that the design so obtained is symmetrical and the line of fold (shown dotted) is the line of symmetry.