1. Lesson 7.1: 1.Vocabulary of Transformations 2.Symmetry 3.Property of Reflection

2. Transformations Vocabulary: Image – by moving all points of a geometric figure according to certain rules, you can create an image of the original figure. Transformation – the process of creating an image

3. Rigid vs. Non-Rigid: Rigid transformation – when an image is congruent to its original figure. Also called an isometry. Preserves size and shape. Non-rigid – a transformation that does not preserve size and shape.

4. 3 Types of Rigid Transformations: Translation (Slide) Rotation (Turn) Reflection (Flip)

5. Translations: Translations are the simplest type of isometry. 3 ways to translate:

6. Rotations: All the points of a figure rotate the same way. The all rotate around a point, called the center of rotation. The figure can move clockwise or counterclockwise.

7. Reflections: Reflections are mirror images over a line of symmetry.

8. Investigation: Using patty paper, follow steps 1-4 on p. 370- 371. Reflection Line Conjecture: The line of reflection is the ________________________ of every segment joining a point in the original figure with its image.

9. Rotational vs. Reflectional Symmetry: Rotational: Reflectional:

10. Practice: Handout 7.1: 1-3, 5-8

11. Homework: p. 373-374: 1-6, 12-14, 18 Review Handout 1-3 with Lesson 7.1 (Definitions & Conjectures)