LINES OF SYMMETRY
If we can reflect (or flip) a figure over a line and the figure appears
unchanged, then the figure has reflection symmetry or line symmetry.
The line that we reflect over is called the line of symmetry.
A line-of symmetry divides a figure into two mirror-image halves.
Some shapes will have no line of symmetry.
Some shapes will have finite lines of symmetry.
Some shapes will have infinite lines of symmetry.
Paper Folding Method
We can imagine the shape given as a paper.
To check the line of symmetry, we have to fold the paper through the line.
If the shapes on both sides of the line get matched, then the line through
which the paper is folded can be considered as line of symmetry.
If the shapes on both sides of the line do not get matched, then the line
through which the paper is folded can not be considered as line of symmetry.
Paper Folding Method Examples
Example 1 :
Is the dotted line on the shape given below a line of symmetry?
, Answer : Yes
Explanation :
We can imagine the above shape given as a paper. If we fold the paper
through the dotted line, transparently the shapes on both the sides of the
line get matched.
So, the dotted line is line of symmetry.
Example 2 :
Is the dotted line on the shape given below a line of symmetry?
If we can reflect (or flip) a figure over a line and the figure appears
unchanged, then the figure has reflection symmetry or line symmetry.
The line that we reflect over is called the line of symmetry.
A line-of symmetry divides a figure into two mirror-image halves.
Some shapes will have no line of symmetry.
Some shapes will have finite lines of symmetry.
Some shapes will have infinite lines of symmetry.
Paper Folding Method
We can imagine the shape given as a paper.
To check the line of symmetry, we have to fold the paper through the line.
If the shapes on both sides of the line get matched, then the line through
which the paper is folded can be considered as line of symmetry.
If the shapes on both sides of the line do not get matched, then the line
through which the paper is folded can not be considered as line of symmetry.
Paper Folding Method Examples
Example 1 :
Is the dotted line on the shape given below a line of symmetry?
, Answer : Yes
Explanation :
We can imagine the above shape given as a paper. If we fold the paper
through the dotted line, transparently the shapes on both the sides of the
line get matched.
So, the dotted line is line of symmetry.
Example 2 :
Is the dotted line on the shape given below a line of symmetry?
