Jazyk:

INVERTED LETTERS

Axial symmetry (Mirroring) 

An object can be called axially symmetric if we can divide it into two mirror-image parts – two parts of the same size and shape. The line that divides an object is called the SYMMETRY AXIS.

Axis mirroring

The square has 4 axes of symmetry.

An equilateral triangle has 3 axes of symmetry.

A regular pentagon has 5 axes of symmetry.

This shape has 1 axis of symmetry. All corresponding parts are at the same distance from the symmetry axis.

Although symmetry is very complicated and elaborate, it is one of the first mathematical concepts that children will understand. Axial symmetry is also called mirror image. Remember it the next time you look in the mirror.

You may be surprised that most people do not have a symmetrical face.

 

Rotational Symmetry (Rotation) 

An object has rotational symmetry if it returns to its original form after rotating a certain angle around a central point.

Rotate around the centre.

The square has a 4-fold rotational symmetry. It returns to its original shape by rotating it 90 °.

The letter H has 2-fold rotational symmetry. It returns to its original shape by rotating it 180 °. – A 180 ° rotation is also called central symmetry.

The recycling symbol has a 3-fold rotational symmetry. It returns to its original shape by rotating it 120 °.

Each regular n-gon has n fold the rotational symmetry.

The asterisk is a great example of rotational symmetry and axial symmetry. It has 5-fold rotational symmetry and 5 axes of symmetry. Imagine finding a starfish on the beach. If you turn it one-fifth, it will look the same.

Is there a perfectly symmetrical shape?