Line Symmetry

Line symmetry is discussed here. We know that any object or shape which can be cut in two equal halves in such a way that both the parts are exactly the same is called symmetrical and the line which divides the shape in two equal halves is called the line of symmetry. A shape can have many lines of symmetry.

Let us follow some of the pictures or figures given below.

(i) Examples of vertical lines of symmetry:

$Vertical Lines of Symmetry$

Vertical Lines of Symmetry

(ii) Examples of horizontal lines of symmetry:

$Horizontal Lines of Symmetry$

Horizontal Lines of Symmetry

Each is divided by a straight line. Both the parts are equal in all respects. When the pictures or figures are folded along the straight lines, one part will fit or cover the other part exactly.

Such pictures or figures of which either of the two parts made by a straight line, covers the other part exactly when folded along this line, are called symmetrical figures. The straight lines are called the lines of symmetry of the respective figures. In the above pictures or figures the lines of symmetry are both horizontal and vertical.

$Horizontal and Vertical Lines of Symmetry$

In the above figure the straight lines shown are not lines of symmetry.

Let us consider some of the symmetrical figures which have been folded along the lines of symmetry:

(i)

$Symmetrical Figures$

(ii)

$Examples of Symmetrical Figures$

These are the basic and main points to understand line symmetry.

Questions and Answers on Line Symmetry:

1. Choose the right answer.

(i) The number of lines of symmetry in a regular pentagon are:

(a) 3

(b) 4

(d) 6

(ii) The number of lines of symmetry in an isosceles triangle:

(a) 1

(b) 2

(d) 4

Answer:

(i) (c)

(ii) (c)

You might like these

Reflection Symmetry | Reflection of the Image| Mirror Line|Symmetrical

If we place a mirror on the line of symmetry we can see the complete image. So, we find that the mirror image or reflection of the image in the mirror and the given figure are exactly symmetrical. This type of symmetry is called reflection symmetry.
Nets of a Solids | Geometry |Nets of a Cube |Nets of a Cone & Cylinder

We will learn how to use nets to find the surface area of a solid? Let us take a box made of cardboard. If we cut open the box and flatten it out, the flat shape is called the net of the box. A net is a two-dimensional shape that can be folded to make a three-dimensional
Definition of Order of Rotational Symmetry | Rotational Symmetry

The number of times a figure fits into itself in one complete rotation is called the order of rotational symmetry. If A° is the smallest angle by which a figure is rotated so that rotated from fits onto the original form, then the order of rotational symmetry is given
What is Rotational Symmetry? | Centre of Rotation | Angle of Rotation

The shapes and objects that look the same after a certain amount of rotation are said to have rotational symmetry. Some shapes look the same after half a turn. If we turn English alphabet S around a centre point by 180° we get the alphabet S in the same position.
Worksheet on Line Symmetry | Geometry Worksheet | Line of Symmetry

Worksheet on line symmetry we will solve different types of questions. 4th grade students can practice this geometry worksheet to get the basic ideas on line symmetry. Fill in the blanks: (i) A square has …... lines of symmetry. (ii) An equilateral triangle has