Symmetry has been catagorized to help us study it. As we look for patterns, we will also learn the language of symmetry. Here are a few definitions to start with. Don't worry too much about them now, but they are here for reference, and will make more sense later.

A **transformation** is an operation which maps, or moves, a figure
to a new position... We will be looking at several transformations.

An **isometry** is a transformation which preserves lengths. That
is a figure is moved, turned, and/or fliped, but it still is the same size
and shape. All transformations we will be working with are isometries.

An image has **Reflectional
Symmetry** if there is at least one line which splits the image in
half so that one side is the mirror image of the other. Reflectional symmetry
is also called **line symmetry** or **mirror symmetry** because there
is a line in the figure where a mirror could be placed, and the figure
would look the same. A reflection is sometimes called a FLIP.

An image has **Rotational
Symmetry** if there is a center point where an object is turned a
certain number of degrees and still look the same. A rotation is sometimes called a TURN.

An image has **Translational
Symmetry** if it can be divided by straight lines into a sequence
of identical figures. Translational symmetry results from moving a figure
a certain distance in a certain direction also called translating (moving)
by a vector (length and direction). A translation is sometimes called a SLIDE.

Extensions:

Java Activities

*Next: ***Reflectional
Symmetry**