Lesson 2, Rigid Movements
- Arpit Kesharwani
Naming The Moves
UNIT 1 • LESSON 2 NAMING THE MOVES
- Setting the Stage
- 2.1: A Pair of Quadrilaterals
- 2.2: How Did You Make That Move?
- 2.3: Move Card Sort
- Identify and describe translations, rotations, and reflections.
- Understand and explain that a reflection changes a figure so that it is “facing” the other direction.
- Introduce the terms translation, rotation, reflection, image, and corresponding points.
- Demonstrating that I know the difference between translations, rotations, and reflections.
- Being able to identify corresponding points before and after a transformation.
- Describe each move or say if it is a new move.
- Frame 1 to Frame 2.
- Frame 2 to Frame 3.
- Frame 3 to Frame 4.
- Frame 4 to Frame 5.
- Frame 5 to Frame 6.
- How would you describe the new move?
- A translation slides a figure without turning it. Every point in the figure goes the same distance in the same direction. For example, Figure A was translated down and to the left, as shown by the arrows. Figure B is a translation of Figure A.
- A rotation turns a figure about a point, called the center of the rotation. Every point on the figure goes in a circle around the center and makes the same angle. The rotation can be clockwise, going in the same direction as the hands of a clock, or counterclockwise, going in the other direction. For example, Figure A was rotated 45º clockwise around its bottom vertex. Figure C is a rotation of Figure A.
- A reflection places points on the opposite side of a reflection line. The mirror image is a backwards copy of the original figure. The reflection line shows where the mirror should stand. For example, Figure A was reflected across the dotted line. Figure D is a reflection of Figure A.