# Free Symmetry 02 Practice Test - 7th grade

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

A.

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

B.

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

C.

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

D. All of the above.

#### 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.

The letter S has ___.

A.

line symmetry

B.

rotational symmetry

C.

both line and rotational symmetry

D.

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.

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.

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.

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.

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

A.

n + 1

B.

n

C.

2n

D.

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.

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

A.

True

B.

False

#### SOLUTION

Solution : B

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

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

A.

True

B.

False

#### SOLUTION

Solution : A

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

Letter C has rotational symmetry of order more than 1.

A.

True

B.

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.

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

A. True
B. False

#### SOLUTION

Solution : B

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