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Symmetry

Let us consider the following mask.

If we cut this mask exactly from middle, we obtain two halves of the mask as shown below.

We can observe that both left and right half faces are exact copies of each other.

Similarly, if we fold the following pictures from the middle, then the left half of the picture will exactly overlap over the right half of the picture.

Such figures are known as symmetrical figures or symmetric.

If we place a mirror on the line where we folded these pictures, then we will find that the image of one half of the figure is exactly the same as the other half.

Symmetry is something that we observe in many places in our daily lives without even noticing it. It is easily noticeable in various arts, buildings, and monuments. Nature uses symmetry to make things beautiful. For example, consider the pictures of the butterfly and the leaf drawn below.

Let us also consider the following pictures.

In each of these pictures, the dotted line divides the picture into two parts such that the left half of the picture is exactly same as the right half. This dotted line is known as the line of symmetry or mirror line. It can be defined as:

 The line through which the figure can be folded to form two identical figures is called line of symmetry or axis of symmetry or mirror line.

Let us consider the following isosceles triangle.

If we draw a dotted line at the middle of the triangle, then we get two parts such that the left part is exactly same as right part.

Here, the dotted line is the …

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