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Encapsulate
math

SYmmETRY

Definition: An object is said to be symmetric if it can be divided into two identical halves.

Line of Symmetry Reflection Symmetry

The line that divides the object into two • The image of an object formed in a plane mirror
identical halves is called a line of symmetry. is of the same shape and size and is formed at
Types of Lines of Symmetry an equal distance from the mirror.

1. Horizontal line of
symmetry
(Object) (Image)
2. Vertical line of symmetry
• Reflection symmetry happens when a figure
can be split into two parts, and one part is like
3. Diagonal line of symmetry a mirror image of the other.

Symmetry in Geometrical Shapes
Rectangle Equilateral Triangle

2 3
Square Circle
Rotational Symmetry

An object is said to have rotational symmetry
4 Infinite if, after rotation about a certain angle, it looks
exactly the same as the original object.
Tile Pattern or Tessellation • The fixed point about which the
object turns is called centre of D A
In regular tile patterns only equilateral rotation.
triangles, squares, and hexagon can be • The angle through which the C B
duplicated infinitely to fill a plane without object looks exactly the same is called angle
gap. of rotation?
• The number of rotations which make the figure
coincides with its original position is called an
order of rotational symmetry.
360°
Triangle Square Hexagon Order of rotational symmetry =
Pattern Pattern Pattern Angle of rotation

Brain Sizzlers

Shalini's mom went to the Banjara market and bought a mystery box from there, that is
password protected. The password consists of English letters (in alphabetical order) that
have only a vertical line of symmetry, followed by the digits 0-9, which have two lines of
symmetry.
Help Shalini to find the password of the mystery box.

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