Symmetrical shapes are discussed here in this topic.
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. The line which divides the shape is called the symmetry. So, if we place a mirror on the line of symmetry we can see the complete image.
When a symmetrical shape is folded along the line of symmetry, one half of the shape exactly lies over the other half which shows that one half of the shape is exactly the same as the other half.
There are many things around us which are symmetrical. Look at the following pictures and observe.
We know that in one symmetrical figure may have more than one line of symmetry.
Some symmetrical shapes have one line of symmetry, some have two and some have more than two, as shown below:
(i) Examples of the shapes having one-line symmetry:
Some shape may have two or more lines of symmetry like a circle has infinite lines of symmetry. A square has four lines of symmetry. A rectangle has two lines of symmetry.
(ii) Examples of the shapes having two - lines symmetry:
Two – Lines Symmetry
(iii) Examples of the shapes having three - lines symmetry:
Three – Lines Symmetry
(iv) Examples of the shapes having four - lines symmetry:
Four – Lines Symmetry
(v) Examples of the shapes having many - lines symmetry:
Many – Lines Symmetry
The line which divides the shape into two equal parts from top to bottom is called the vertical line of symmetry.
Some objects have a horizontal line of symmetry which divides the shape into equal parts from left to right side.
Thus we may conclude that;
(i) Some shapes have no line of symmetry,
(ii) some have one line of symmetry,
(iii) some have two,
(iv) some have three and
(v) some have many lines of symmetry.
A circle has innumerable lines of symmetry that pass through its centre,
The knowledge of symmetrical shapes and lines of symmetry is very useful for making symmetrical designs.
Related Concepts on Geometry - Simple Shapes & Circle