1.6 Motion in Geometry

Rigid Transformations Transformations that do not change shape or size. Pre-image is the original shape Image is the shape that undergoes a transformation

NOTATION The original figure is named as we have learned so far. For instance a point would be called A. This is the pre-image. The image of point A is called A’ (said, “A prime”). This is so we can tell the difference between the 2 identical figures.

Transformations There are 3 types of rigid transformations: Translation – shapes slide Rotation – shapes turn Reflection – shapes flip

Translation Shapes slide Every point of a figure moves in a straight line, all points move the same distance and same direction. WHO HAS EXTRA PATTY PAPER? Activity 1, pg 51

Rotation Rotations turn Every point of a figure moves around a given point called the center of rotation. Activity 2, pg 51

Reflection Reflections flip. In a reflection, a line plays the role of a mirror. Every point in a figure is ‘flipped’ across the line.

Summary What is the movement of a rotation? What does is ‘turn’ around? What is the movement of a translation? What does it ‘slide’ on? What is the movement of a reflection? What does it ‘flip’ over? When can the pre-image and the image be a different size? How do you notate the pre-image? (For instance segment AB) How do you notate the image?

Game of War Get a partner, a pencil and one piece of paper. Fold the paper hamburger On your side, put 5 war things no bigger than a dime. Don’t group them together, spread them out. Try and hit the other person’s items by drawing a bomb on your side, folding the paper and tracing the bomb.

BONUS!!!! I’m looking for two things….. Tell me the relationship between the pre-image of the bomb and the image of the bomb with the fold line. Tell me the relationship between a segment drawn between the pre-image and image of a bomb with the fold line.

Assignment Worksheets 1.6 A and 1.6 B