Idea of Rotational Symmetry, Observations of Rotational Symmetry Of 2-D Objects



A figure which does not change upon undergoing a reflection has reflection symmetry.

An object or figure which is indistinguishable from its transformed image is called mirror symmetric.

Reflection Symmetry:

Reflectional symmetry occurs when a line is used to split an object or shape in halves so that each half reflects the other half. Sometimes objects or shapes have more than one line of symmetry.

For example, let us consider the alphabet ‘H’. How many lines of symmetry does it have?

Answer: 2.

There are two ways to draw a line so that each half reflects the other half. 



Many letters of the alphabet have reflectional symmetry. Some use a vertical line; some use a horizonatal line.

Geometric shapes can also demonstrate reflectional symmetry, such as circles and squares, which have four lines of symmetry.


Depending on the type of triangle, one may have zero, one or three lines of symmetry. 

While some shapes have one, two, or many lines of symmetry, some have none.

 Take the letter N for example, while it demonstrates point symmetry, it does not have reflectional symmetry.

 It is also possible for some shapes to have an infinite number of reflected images.