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This symmetry is also known as line symmetry or mirror symmetry. And this line of symmetry
can be in any direction, horizontal, vertical, or slanting.

activity
Take a piece of paper and fold it in half into any direction, i.e., horizontally or
vertically. Spill few drops of ink on one half side of the paper.
Now, fold the paper along its crease which has been made by folding paper earlier and
press the halves together.

Unfold the paper and find two identical parts of an image formed by splitting ink’s drops
on both sides of crease. We can clearly observe that the figure formed is symmetric.

The crease or the line of fold is an example of line of symmetry.

PLANE SYMMETRY

Let us take a round orange and slice it with a knife into two halves.
It creates a plane of symmetry of the orange.

A 3D shape has plane symmetry if it can be divided into
two halves by a plane and have each half be a reflection
of the other across the plane.
The plane is called a plane of symmetry of the 3D figure.

Look at these 3D figures and their plane of symmetry.

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Multiple Planes of Symmetry

Geometric solids can have multiple planes of symmetry.
For example, the cube has nine planes of symmetry.

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