All About Symmetry
In this section we will cover two basic types of symmetry within geometry:
Rotational and Reflectional
A figure has rotational symmetry if, when it is turned a certain amount of degrees between 0 and 360, the image itself looks the same.
Rotational symmetry could relate to central angles for in a polygon such as a regular hexagon, where its central angle is 60 degrees, every 60 degree it is rotated it has symmetry.
What you are doing in rotational symmetry is basically turning a figure around various times around its own mid-point.
Reflectional symmetry is a translation across a line, where one side of a image/figure is the reflection (like in a mirror) of the other side of the image.
This line can be across the y-axis or the x-axis and for it to be a perfect reflection, the picture must be able to fold and match perfectly.
Various polygons have reflection symmetry such as depicted in the picture above.