In this chapter we will look at the concept of reflection symmetry with properties and examples.

## What is Reflection symmetry ?

Reflection symmetry is also known as **line symmetry** or **mirror** **symmetry** in geometry.

In reflection symmetry, **a reflection image is formed across the axis of symmetry**.

Hence in reflection symmetry,** one part of image is the mirror image of another**.

For example;

Note the image of car above.

The yellow line MN is called the line of symmetry.

Note that the right part of the image is the reflection of left part separated by axis line MN.

**Example 02**

English letter ” A “

Here the red line MN is axis of symmetry.

The right part of alphabet is the mirror image of the left part.

**Example 03**

Given above is the object and its mirror image separated by line of symmetry MN.

### What is Line of symmetry ?

Line of symmetry is the **axis around which the mirror image form**.

There can be** different lines of symmetry**;

(a) Horizontal line of symmetry

(b) Vertical line of symmetry

(c) Diagonal line of symmetry

Let us understand each of the above in detail.

#### Horizontal line of symmetry

The** horizontal line around which the mirror image is formed** is called horizontal line of symmetry.

For example;

Given above is the object and mirror image across the horizontal line of symmetry MN.

**Example 02**

#### Vertical line of symmetry

The **vertical line across which the reflection forms** is called Vertical line of symmetry.

For example;

Given above is the object ” CROSS ” and its reflection image.

Note that it’s the vertical axis PQ across which the reflection forms.

**Example 02**

#### Diagonal line of Symmetry

A **tilted straight line across which reflection occurs** is called diagonal line of symmetry.

**For example**;

Given above is the **square ABCD** and **MN is the diagonal axis of symmetry across w**hich reflection images formed.