Theory:

Figures with exactly two lines of symmetry:
 
We all know that a figure can contain two or more lines of symmetry.
 
Let us look at a few examples with exactly two lines of symmetry.
Picture1.png
 
In the above example, the same shape can be cut into two identical halves in two different ways.
 
So the same shape with both the lines of symmetry will look like this.
Picture2.png
Let us also look at a few more examples with exactly two lines of symmetry.
 
Shape
Lines of symmetry
Final figure
Picture4.png
Picture3.png
Picture5.png
Picture8.png
Picture6.png
Picture7.png
Picture10.png
Picture9.png
Picture11.png
 
The shapes mentioned above will only have precisely two lines of symmetry. No other line can cut these shapes into identical halves.
 
  
Figures with two or more lines of symmetry:
 
In a few cases, there can be two or more lines of symmetry.
 
Consider the following figure:
1(1).png
 
The final figure will look like this:
 
2(1).png
 
A square has four equal sides. So it is a regular polygon.
 
A square has \(4\) lines of symmetry.
 
In case of regular polygons, the number of lines of symmetry equals the number of sides.
 
A polygon:
If three or more line segments form a closed surface, then it is a polygon. The line segment can be of any length.
Regular polygon:
If three or more line segments of equal length form a closed surface, then it is called a regular polygon. Equilateral triangle, square, pentagon and hexagon are a few examples of regular polygon.
Let us look at a few more examples.
 
Shape
Number of sides
Lines of symmetry
Final figure
5(1).png
\(3\)
3.png
4(1).png
8(1).png
\(5\)
7(1).png
6(1).png
11(1).png
\(6\)
9(1).png
10(1).png