It's important that you are able to tell the difference between rotational and reflectional symmetry and that you can go one step further and create your own shapes that have these types of symmetries. Let's begin with some examples, and then you will complete an activity that will allow you the opportunity to create your own symmetries.
Work through the following slides to see the differences between rotational and reflectional symmetries.
Rotational Symmetry
This figure has 120° rotational symmetry and no reflectional symmetry. Notice that no matter where we try to place the line of symmetry, the right and left hand sides will not be mirror images of each other. Reflectional Symmetry
This figure has reflectional symmetry. The line of symmetry is shown above. The only way to rotate this figure is a full 360° rotation; therefore, it does not have rotation symmetry. Both Symmetries
This figure exhibits both rotational and reflectional symmetry. It has an angle of rotation of 90° and has the four lines of symmetry pictured above. |
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Now, it's your turn to create your own rotational and reflectional symmetries. Click the Activity button to access the worksheet. When you have completed the worksheet, submit it to your teacher.
