Rotational Symmetry

Q.

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

Q.

State the number of lines of symmetry for the following figures:

(a) 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

Q.

Order of symmetry, angle of rotation of isosceles triangle

Q. Which of the following figures has no line of symmetry but has rotational symmetry of order 2?

1. Square
2. Parallelogram
3. Rectangle
4. None of the above

Q. The letters H and Z have both line symmetry and rotational symmetry.

1. True
2. False

Q.

Draw, wherever possible, a rough sketch of

(i) a triangle with both line and rotational symmetries of order more than 1.

(ii) a triangle with only line symmetry and no rotational symmetry of order more than 1.

(iii) a quadrilateral with a rotational symmetry of order more than 1 but not a line symmetry.

(iv) a quadrilateral with line symmetry but not a rotational symmetry of order more than 1.

Q.

Which of the following has no rotational symmetry?

1. 

2. 

3. 

4. 

Q.

Which shape has infinite line of symmetry ?

1. A circle

2. A parallelogram

3. A rectangle

4. A triangle

Q.

Letter C has rotational symmetry of order more than 1.

1. True

2. False

Q. Question 6
After rotating by ${60}^{\circ }$ about a centre, a figure looks exactly the same as its original position. At what other angles will this happen for the figure?

Q.

The order of rotational symmetry of the given figure about its centre is:

1. $2$

2. $3$

3. $0$

4. $1$

Q. Question 5
The order of rotational symmetry in the figure given below is

a) 4
b) 8
c) 6
d) Infinitely many

Q.

Question 45
Fill in the blank to make statement true.
Each of the letters H, N, S and Z has a rotational symmetry of order ___.

Q.

Through what angle in degrees does the minute hand of a clock rotate in $20min$?

Q.

Fill in the blanks :

The angle by which an object rotates is called the angle of ________.

Q.

Which of the following figures have both line symmetry and rotational symmetry?

(i) Square
(ii) Rectangle
(iii) Scalene triangle
(iv) Isosceles triangle

1. Only i

2. i, ii, iii and iv

3. i, ii and iv

4. i, ii

Q.

Rhombus is a figure that has ______lines of symmetry and has rotational symmetry of order _______.

Q. Question 6
The order of rotational symmetry in the figure given below is

a) 4
b) 2
c) 1
d) Infinitely many

Q.

If a fan has 3 blades, then its degree of rotation is _____.

1. ${90}^{\circ }$

2. ${150}^{\circ }$

3. ${120}^{\circ }$

4. ${180}^{\circ }$

Q.

Question 66
State whether the statement is True or False.
Order of rotational symmetry of a rhombus is four.

Q. What is the order of the rotational symmetry of the given figure about the point marked ‘x’?

1. $0$
2. $1$
3. $2$
4. $3$

Q.

Question 47
Fill in the blank to make statement true.
Order of rotational symmetry of a circle is ___.

Q.

Question 68
State whether the statement is True or False.
Order of rotational of a semicircle is two.

Q.

Look at the adjoining figure, what is the order of rotational symmetry about point X?

1. 6

2. 5

3. 4

4. 8

Q. How many order of rotational symmetry a rhombus has?

1. Zero
2. One
3. Two
4. Three

Q.

Question 31
Fill in the blank to make the statement true.
___ triangle is a figure that has a line of symmetry but lacks rotational symmetry.

Q.

Which of the following figures has/have both line symmetry and rotational symmetry?

(i) Square (iii) Pentagon

(ii) Rectangle (iv) Isosceles triangle

1. Only i

2. i, ii

3. i, ii, iii and iv

4. i, ii and iv

Q.

How many angles of rotation a regular polygon will have if it has ‘n’ sides?

1. $n$

2. $n-1$

3. $n+1$

4. $\frac{n}{2}$

Q.

If a fan has a rotational symmetry of order 4, how many blades it has?

1. 3

2. 4

3. 5

4. 2

Q.

Question 119
Tell whether each figure has rotational symmetry. Write yes or no.