1. Section 7.1 Rigid Motion in a Plane

2. BellWork Come in quickly and quietly. Have out your calculator and pencil. No Assessment is to be done in PEN. You may quietly review for your assessment with notes and your assessment review. If your Review is not graded, turn it in to the Guest Teacher. After attendance you will begin your test. Please do not write on the purple “Cheat Sheet”. These will be collected and re-used for other classes. After the test, begin this ppt and see what fun things are in section 7.1! Be Good and I will see you Friday.

3. Outcomes You will be able to identify the three basic rigid motion transformations. You will be able to identify and define an isometry.

4. Transformations A transformation is a change in the __size_, _location_, or _orientation_ of a figure. An Isometry is a transformation that preserves length, angle measures, parallel lines, and distances between points. Transformations that are isometries are called Rigid Motion Transformations. Isometry

5. Rigid Motion Transformations There are three kinds of rigid motion transformations: – Rotation – a “swing” around a point – Reflection – a “flip” over a line – Translation - a slide in one direction

6. Transformations A reflection is a transformation which flips the figure over a line. This line is called the line of reflection.

7. Transformations Rotation – A rotation is a transformation in which a figure is rotated about a fixed point, called the center of rotation.

8. Transformations A translation is a transformation which slides each point of a figure the same distance and in the same direction.

9. Translation The resulting figure after a transformation is called the image of the original, or preimage. Preimage Image A A’ B C B’ C’ Notice the labels on the image. We say “A prime”.

10. Preimage and Image Based on the arrow on the diagrams, label the images and preimages.

11. Translation Example 1: ΔABC is translated 1 unit right and 4 units up. Draw the image ΔA’B’C’. What are the coordinates of : A (, ) ⤍ A’(, ) B(, ) ⤍ B’(, ) C(, ) ⤍ C’(, ) Is the preimage and image congruent to each other?

12. Isometry Not IsometryIsometry

13. Mapping Mapping – describes any transformation with arrow notation. You can describe “ ΔABC is mapped onto ΔDEF” using this notation: ΔABC ⟶ ΔDEF Like a congruency statement, the order of the letters matter! ΔABC ⟶ ΔDEF ΔPQR ⟶ ΔXYZ

14. Your IP is in the textbook! Pages 399-401: problems 5-39 odds.