Question

Some English alphabets have fascinating symmetrical structures. From the following table, find the number of alphabets which have both the lines symmetry and rotational symmetry as 2.

Alphabets	Line Symmetry	Number of lines symmetry	Rotational symmetry	Order of rotational symmetry
Z	No	0	Yes	2
S	No	0	Yes	2
H	Yes	2	Yes	2
O	Yes	2	Yes	2
I	Yes	2	Yes	2
N	No	0	Yes	2
C	Yes	1	No	1

Answer 1

Hint:
Here we will first read the table carefully. We will find the alphabet which has 2 lines of symmetry and has 2 rotational symmetries. Then we will count the total number of such alphabets in the table to get the required answer.

Complete step by step solution:
Here we need to find the number of alphabets that have a line of symmetry as 2 and rotational symmetry as 2.
Symmetry is defined as the quality of being made of exactly similar parts facing each other or around an axis. A line of symmetry is defined as a line that divides the object into 2 equal parts or two equal halves.
Now, from the table, we can see that letter ‘H’, letter ‘O’, and the letter ‘I’ have 2 lines of symmetries and 2 rotational symmetries but the letters don’t have both lines of symmetry and rotational symmetry as 2.
Therefore, the number of alphabets which have both the lines symmetry and rotational symmetry as 2 are equal to 3 i.e. letter ‘H’, letter ‘O’, and letter ‘I’.

Hence, the required number of letters is 3.

Note:
A shape or an object is said to have rotational symmetry when they look the same after some rotation and the number of such rotations is known as the order of rotation of any object or shape.
Generally, there are three types of Symmetry:
1) Radial symmetry: It is the symmetry in which the object looks symmetric about its center like a pie.
2) Bilateral symmetry: It is the type of symmetric in which the object is divided by an axis and on both sides of the axis the object looks the same.
3) Spherical symmetry: It is the type of symmetric in which the object is cut through its center, resulting in both the parts looking the same.