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Q1.

• 1)
• 2)
• 3)
• 4)

Solution

Q2. Draw a triangle with one line of symmetry and rotational symmetry of order one.

Solution

The triangle is as below: The line of symmetry is: Clearly the figure has rotational symmetry of order one only.

Q3. Find the number of lines of symmetry of the following figures: (i) A circle (ii) A rhombus (iii) An equilateral triangle (iv) A parallelogram

Solution

Number of lines of symmetry are: (i) A circle, infinite lines of symmetry (ii) A rhombus, two lines of symmetry (iii) An equilateral triangle, three lines of symmetry (iv) A parallelogram, no line of symmetry

Q4. Colour the square boxes assuming the dark brown line to be a mirror line.

Solution

After colouring the square boxes, the required image is as below:

Q5. Which of the following figure depicts reflectional symmetry?

• 1)
• 2)
• 3)
• 4)

Solution

The figure given in option (C) when folded on dotted line, overlaps completely, hence dotted line acts as mirror.

Q6. A regular pentagon has

• 1) 4 lines of symmetry
• 2) 5 lines of symmetry
• 3) 6 lines of symmetry
• 4) 7 lines of symmetry

Solution

Number of sides of a polygon is equal to its lines of Symmetry. So, pentagon has 5 lines of symmetry.

Q7. Consider the following letter M, draw its image after a quarter turn and a half turn in clockwise direction.

Solution

Image after quarter turn in clockwise direction is:Image after half turn in clockwise direction is:

Q8. Which of the following alphabet has reflectional symmetry?

• 1)
• 2)
• 3)
• 4)

Solution

The figure in option (D) when folded on dotted line overlap completely, hence dotted line act as mirror.

Q9. Complete the table given below:

Solution

Line of symmetry: Rotational Symmetry:Thus, the completed table is as below:

Q10. A square has an angle of rotation of ______.

• 1) 50^o
• 2) 90^o
• 3) 60^o
• 4) 180^o

Solution

For regular polygon,

Q11. Draw the lines of symmetry in the following polygon and count them.

Solution

7 lines of symmetry.

Q12. Consider the following letters A and B, draw their images after a half turn in clockwise direction.

Solution

Images after a half turn in clockwise direction are as below:

Q13. Give an example of an alphabet which has 2 lines of symmetry as well as rotational symmetry of order 2.

Solution

The alphabet is: H It has 2 lines of symmetry as shown below:After rotating the letter H through 180^o, we find that the image remains same. So the order of rotational symmetry is 2.

Q14. A regular ______ is symmetric when rotated by an angle of rotation of 45^o.

• 1) Octagon
• 2) Septagon
• 3) Triangle
• 4) Hexagon

Solution

For regular polygon, Angle of rotation = Thus, number of sides =   And, Octagon has 8 sides. Hence, option (C).

Q15. Which of the following letter has only rotational symmetry i.e. there is no line symmetry?

• 1) A
• 2) S
• 3) Z
• 4) N

Solution

The only letter among the given option is S which can be rotated at an angle of 180⁰, to hold the symmetry.

Q16. In the following diagram, identify the line of symmetry and order of rotational symmetry.

Solution

The diagram has 2 lines of symmetry as shown below: After rotating the diagram through 180^o, we find that the image remains same. So the order of rotational symmetry is 2.

Q17. If the given line represents line of reflection then draw the image after reflection. (i) (ii)

Solution

The reflection can be drawn as below: (i) (ii)

Q18. If the following image rotates about the point x then find the order of symmetry and the angle of symmetry.

Solution

After rotating through 90^o, it gives the same image, so the angle of symmetry is 90^o. Also through a complete turn it looks similar 4 times at each 90^o turn. Hence the order of symmetry is 4.

Q19. Colour the square boxes assuming the dark brown line to be a mirror line.

Solution

After colouring the square boxes, the required image is as below: