Symmetry And Line of Symmetry

We observe symmetry in any object if it can be split into two identical halves. Asymmetric indicates that an item cannot be split into two identical parts.

This teaching guide aims at making the idea of symmetry more understandable and aid educators by offering teaching resources including animated stories, eye-catching posters, and practical activities.

## Symmetrical And Asymmetrical Shapes

• When 2 halves of any object show exact resemblance or similarity, it is said to be symmetrical.
• In symmetrical shapes, one half of the object acts as the mirror image of the other object.

## Line Of Symmetry

• A line of symmetry is an imaginary line that passes through the centre of any symmetrical shape.
• Any symmetrical shape can be folded into 2 equal and identical halves along its line of symmetry.

## Different Types of Symmetry

Vertical Line of Symmetry :

This is a line that runs up and down and divides an object into two identical halves. For instance, if we have a shape that can be split into two equal halves by a straight line running vertically, we say it has a vertical line of symmetry.

Horizontal Line of Symmetry :

This is a line that divides a shape into two identical halves when it is split horizontally, either from right to left or vice versa. For example, if a shape can be split into two equal parts by a horizontal line, it has a horizontal line of symmetry.

Diagonal Line of Symmetry :

This is a line that divides a shape into two identical halves when it is split along the diagonal corners. For instance, if we can split a square shape into two equal halves by cutting it across the corners, we say it has a diagonal line of symmetry.

## Number of Lines of Symmetry

One Line of Symmetry :

Shapes with one line of symmetry are only symmetrical about one axis. This axis can be horizontal, vertical, or diagonal. For example, the letter “A” has one line of symmetry, which is the vertical line down its center.

Two Lines of Symmetry :

Shapes with two lines of symmetry are symmetrical about two different lines. These lines can be vertical, horizontal, or diagonal. For example, a rectangle has two lines of symmetry: one vertical and one horizontal.

Infinite Lines of Symmetry :

Shapes with infinite lines of symmetry are symmetrical about multiple lines. These lines can be vertical, horizontal, or diagonal. Again, a rectangle is an example of a shape with infinite lines of symmetry because it has an infinite number of vertical and horizontal lines that divide it into identical halves.

## Types of Symmetry

Symmetry can be observed in different ways when we flip, turn, or slide an object. There are four types of symmetry.

Reflective Symmetry In 2D Shapes

• When one half of the shape or object is the reflection of the other half, it exhibits reflective symmetry.
• A shape or pattern which is reflected along its line of symmetry.
• A line of symmetry divides the shape into its 2 mirror images.
• A shape should have at least one line of symmetry to show reflective symmetry.

Rotational Symmetry In 2D Shapes

• When any shape looks the same on being rotated more than half a turn is said to show rotational symmetry.
• It is also called radial symmetry.
• The number of times the shape fits into its boundary exactly while taking one complete rotation is called the order of rotational symmetry.
• For example- An Equilateral Triangle with an order of symmetry as 3.

## Transformations: Reflection, Rotation, And Translation

When there is any change in the appearance of the figure it is said to show transformation. There are 4 types of transformations.

• Translation occurs when any figure slides in one direction.
• Reflection occurs when any figure flips over a line.
• Rotation occurs when any figure rotates to a certain degree around a point.
• Dilation occurs when any figure expands or contracts keeping its shape the same. It is also called resizing.

Posters

Teaching symmetry with kid-friendly, clear, and easy-to-understand posters from Uncle Math School by Fun2Do Labs :

Stories

Ignite kids’ curiosity with engaging stories for role play and skits, making the learning of this concept an exciting and effective experience. Teaching symmetry through stories from Uncle Math School by Fun2Do Labs :

Text of Stories

Activities

Learning symmetry can be made enjoyable by incorporating interactive games and activities.

### Symmetry Hunt

This is one of the most exhilarating activities for children to understand the concept of symmetry. This activity can be carried out in the following steps :

• Take children outdoors and instruct them to collect 3 symmetric and 3 asymmetric objects, they see around them like flowers, leaves, rocks, feathers, etc.
• Children can trace their collections on a page and label them as symmetric and asymmetric shapes.

Worksheets

Help your kids practise symmetry with interesting and engaging fun worksheets and solutions from Uncle Math by Fun2Do Labs.

Worksheet 474 : Line Of Symmetry
Solution 474 : Line Of Symmetry
Worksheet 475 : Line Of Symmetry
Solution 475 : Line Of Symmetry
Worksheet 476 : Symmetrical Objects
Solution 476 : Symmetrical Objects
Worksheet 477 : Symmetrical Alphabets
Solution 477 : Symmetrical Alphabets
Worksheet 478 : Lines Of Symmetry
Solution 478 : Lines Of Symmetry
Worksheet 479 : Symmetrical Alphabets
Solution 479 : Symmetrical Alphabets
Worksheet 480 : Translation, Reflection And Rotation
Solution 480 : Translation, Reflection And Rotation
Worksheet 481 : Reflection, Rotation And Transition
Solution 481 : Reflection, Rotation And Transition
Worksheet 482 : Reflection, Rotation And Translation
Solution 482 : Reflection, Rotation And Translation
Worksheet 483 : Order Of Symmetry
Solution 483 : Order Of Symmetry