Activity: Symmetry of Shapes

shapes page thumb  

Let's find symmetry in shapes!

You will need some shapes. You could buy some, or make your own like this:

Folding Test

You can find if a shape has a Line of Symmetry by folding it.

When the folded part sits perfectly on top (all edges matching), then the fold line is a Line of Symmetry.

Here I have folded a rectangle one way, and it didn't work.

symmetry folding no
So this is not a Line of Symmetry

But when I try it this way, it does work (the folded part sits perfectly on top, all edges matching):

symmetry folding yes
So this is a Line of Symmetry

An Octagon

Let us try the Octagon (the 8-sided shape)

Is this a Line of Symmetry?

octagon maybe symmetry

Let's try folding it:

octagon yes symmetry

Yes! When folded over, the edges match perfectly

So let us draw it on:

octagon draw line symmetry

I found another way too::

octagon try octagon works
Tried this It works!

So let us draw it on, too:

octagon draw

In fact I found 8 Lines of Symmetry:

octagon 8 lines symmetry


How about this Triangle? triangle
I tried this fold, but it didn't work: triangle not symmetry

Can you find any Lines of Symmetry in that triangle? I couldn't.

But how about other types of triangle?

Your Turn

Now it is your turn ... pick a shape and find its Lines of Symmetry.

In fact, try them all! See what you discover.



Final Note: The Circle

How about the Circle? Did you find any Lines of Symmetry?

In fact the circle has infinite Lines of Symmetry, how about that!

  circle symmetry