In our day to day activity we see many leaves of plants, blades, wings of butterflies etc.

__Introduction of symmetry __

In our day to day activity we see
many leaves of plants, blades, wings of **butterflies etc.**

The figures which can be divided
into two parts of equal shape and size are called symmetrical figures.

**EXAMPLE**

The two halves of the figures are
the mirror images of each other.

**EXAMPLE**

**Activity**

**•** Draw the mirror symmetry using the
other half.

**Symmetry**

The line which divides a figure into two equal halves is called the line
of symmetry.

**Symmetry in Geometrical shapes**

A
square has four lines of symmetry

A rectangle has two lines
of symmetry.

A
circle has infinite lines of symmetry

An
equilateral triangle has three lines
of symmetry

**Activity**

Find out the symmetrical figure
and colour it:

__1. ____Able
to explore intuitively the reflections through mirror ink blots, paper cutting
and paper folding:__

**Activity**

• Take a piece of
paper. Fold it exactly into half. Now take the folded edge and fold it into
itself. Cut from one folded edge to the other folded edge. Open the paper and
get a symmetrical figure.

**Activity**

Let us understand the concept of
symmetry by paper folding:

**•** Take a white sheet
of paper and fold it once such that it is divided into two equal parts.

**• **Mark any two points say A and B on the folded line. As
shown in figure.

**• **Draw a closed figure on the folded paper beginning at a
point and ending at the other point.

**• **Cut the closed figure along the dotted lines marked.

**• **Unfold the paper. The half shapes on the either side of the
line of fold AB are exactly the same.

**• **The line of the fold is the line of symmetry.

__2. Able to draw top
view, front view and side view of simple objects.__

__3. To observe from
the surroundings and from day to day life situations and identify symmetrical
objects.__

**Activity**

Check whether the following pictures are
symmetrical or not symmetrical

__4. Collects record
symmetrical objects whenever / wherever they see.__

**Activity**

**•**** **Observe the objects around you at home. List the name and shape of the
objects. Above these objects which can be called as symmetrical.

**Name : Shape**

1. Clock - Circle

2. Television - Rectangle

3. Funnel - Cone

4. Books - Rectangle

5. Match boxes - Rectangle

6. Carom board - Square

7. Orange - Sphere

__5. To draw such
symmetrical objects and naming the same.__

Tags : Geometry | Term 2 Chapter 1 | 4th Maths , 4th Maths : Term 2 Unit 1 : Geometry

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4th Maths : Term 2 Unit 1 : Geometry : Introduction of symmetry | Geometry | Term 2 Chapter 1 | 4th Maths

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