# Free Symmetry 02 Practice Test - 7th grade

### Question 1

Which of the following is correct with respect to reflection symmetry of letters of the English alphabets?

Letters A, H, I, M and W have reflection symmetry about a vertical mirror.

Letters B, C, D, E and H have reflection symmetry about a horizontal mirror.

Letters O and X have reflection symmetry about both horizontal and vertical mirrors.

#### SOLUTION

Solution :D

A shape has line symmetry when one half of it is the mirror image of the other half. A mirror line helps us visualise line symmetry.

If a mirror is kept vertically passing through the centre of letters A, H, I, M and W, the exact same reflection appears.

If a mirror is kept horizontally passing through the centre of letters B, C, D, E and H, the exact same reflection appears.Similarly, letters O and X have reflection symmetry about both horizontal and vertical mirrors.

### Question 2

The letter S has ___.

line symmetry

rotational symmetry

both line and rotational symmetry

no symmetry

#### SOLUTION

Solution :B

The letter 'S' when rotated by an angle of 180∘ will look exactly the same as before.

Thus, it has rotational symmetry of order 2.

The letter S does not exhibit line symmetry.

### Question 3

Order of rotational symmetry for a scalene triangle is

#### SOLUTION

Solution :No two sides in a scalene triangle are equal. So, it's not a symmetrical figure. Any object that occupies the same position after a rotation of 360∘ has a rotational symmetry of order 1.

### Question 4

Order of rotational symmetry of the letter X about the point of intersection of the lines is

#### SOLUTION

Solution :Order of rotational symmetry of the letter X about the point of intersection of the lines is 2.

### Question 5

Order of rotational symmetry of an equilateral triangle about the centroid of the triangle is

#### SOLUTION

Solution :Order of rotational symmetry of an equilateral triangle about the centroid of the triangle is 3.

### Question 6

An 'n'-sided regular polygon has ____ lines of symmetry.

n + 1

n

2n

n - 1

#### SOLUTION

Solution :B

A regular polygon has as many lines of symmetry as the number of sides it has.

So, an 'n'-sided regular polygon has 'n' lines of symmetry.

### Question 7

Letters H, O and Z have both line symmetry and rotational symmetry. Say true or false.

True

False

#### SOLUTION

Solution :B

Letters H and O have both line symmetry and rotational symmetry. Z has only rotational symmetry.

### Question 8

Diameter is the line of symmetry of a circle. (True or False)

True

False

#### SOLUTION

Solution :A

The statement is true. Diameter is the line of symmetry of a circle.

### Question 9

Letter C has rotational symmetry of order more than 1.

True

False

#### SOLUTION

Solution :B

If we rotate a figure about a fixed point by a fixed angle (other than 360∘) and obtain the same figure, then it is said to have rotational symmetry of order more than 1.

The letter C does not have rotational symmetry of order more than 1 as it can be rotated only by an angle of 360∘ to come back to its original position.

### Question 10

A figure with angle of rotation as 17∘ has rotational symmetry of order more than 1. Say true or false.

#### SOLUTION

Solution :B

False. As 36017 is not a natural number, a figure can not have an angle of rotation as 17∘.