1. Lesson 7.1
Rigid Motion in a Plane

2. Lesson 7.1 Objectives Identify basic rigid transformations
Define isometry

3. Definition of Transformation
A transformation is any operation that maps, or moves, an object to another location or orientation.

4. Transformation Terms
When performing a transformation, the original figure is called the pre-image.
The new figure is called the image.
Many transformations involve labels
The image is named after the pre-image, by adding a prime symbol (apostrophe)
A A’ A’’
We say it as “A prime”

5. Types of Transformations
Reflection
Rotation
Translation
Characteristics
Orientation
Pictures
Flips object over line of reflection
Turns object using a fixed point as center or rotation
Slides object through a plane
Order in which object is drawn is reversed
Stays same just tilted
Stays same and stays upright

6. Definition of Isometry
An isometry is a transformation that preserves length.
Isometry also preserve angle measures, parallel lines, and distances between points.
If you look at the meaning of the two parts of the word, iso- means same, and metry- means meter or measure.
So simply stated, isometry preserves size.
Any transformation that is an isometry is called a Rigid Transformation.