1. Things Needed Today (TNT): Topic: Congruency & Review of Rotations
Math CC7/8 – May 22
Things Needed Today (TNT):
Pencil/Math Notebook
Transformation Brochure
Math Notebook:
Topic: Congruency & Review of Rotations
HW: Transformation WS

2. What’s Happening Today?
Congruency
Review of Rotations

3. Notes
When making transformations of figures, you need to pay attention to two important things:
_______________ and _______________ .
Distance
Angle

4. Reflection:
Maintain a 90 degree angle with perpendicular bisector
Original point and image must be SAME distance from line of reflection
Rotation:
Mark CENTER of rotation
Measure distance of each point from center of rotation
Rotate each point the same angle
Translation:
Measure distance of slide
Keep parallel lines of slide

5. Are the rules the same for rotations for clockwise & counterclockwise?
When a point (x, y) is rotated counterclockwise about the origin, the following rules are true:
rotation of 900 (x,y) (-y, x).
 rotation of 1800 (x,y) (-x, -y).
rotation of 2700 (x, y) (y, -x).
When a point (x, y) is rotated clockwise about the origin, the following rules are true:
rotation of 900 (x,y) (y, -x).
 rotation of 1800  same as counterclockwise. Since it is a half-turn, the image is the same no matter the direction!
rotation of 2700 (x, y) (-y, x). .

6. Connecting Congruent Polygons

10. Objects are congruent if they are exactly the same shape and size.

11. Are these shapes congruent?

12. Similar objects are the same shape but are not the same size.

13. Are these shapes similar?

14. Matching parts of congruent or similar figures.
Corresponding Parts
Matching parts of congruent or similar figures.

15. What parts are corresponding?B E F C D G H B X Y Z A C

16. Transformations
Translation
Reflection
Rotation
Dilation

17. Translation (Slide) A figure moves along a straight line. Figure 1

18. A mirror image is created across a line.
Reflection (Flip)
A mirror image is created across a line.
Figure 1
Figure 2
Figure 1
Figure 2

19. A figure turns around a point.
Rotation (Turn)
A figure turns around a point.
90°
90°
180°
180°
Figure 2
Figure 1
Figure 1
Figure 2
Figure 2
Figure 2

20. Name the Transformation
Rotation clockwise
90° 1 1
Translation 2 2 1 1 2 2
Rotation
Reflection
180°