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∘.