1. transformations (Rotations)
Today’s Lesson:
What:
transformations (Rotations)
Why:
. . . so I can both identify and perform rotations on the coordinate plane.

2. As a figure is rotated (around the origin) on the coordinate plane, what happens to the original coordinates (x and y) of its points?

3. Short intro to rotations . . .

4. What about rotations ?? Stations of Rotation: 90º: 180º: 270º: 360º:
CLOCKWISE: from “12 o’clock” (top of coordinate graph), figure will rotate to the ____________________.
COUNTER-CLOCKWISE: from “12 o’clock” (top of coordinate graph), figure will rotate to the _____________.
𝟏 𝟒 turn
𝟏 𝟐 turn
𝟑 𝟒 turn
full turn
right
left

5. 90° 270° 180° Clockwise Rotation Example . . .
If you focus on the right angle on each figure, you can see how the figure itself is rotating as it travels around the coordinate plane.

6. Original Coordinates:
Rotating a triangle (together in class) . . .
Counter-clockwise: AI BI CI A B C AI BI CI AI BI CI
Original Coordinates:
A (2, 1)
B (2, 7)
C (6, 1)
90º
Quadrant ________
A ( , )
B ( , )
C ( , )
180º
270º
360º II
III IV I

7. Wrap-it-up/summary: As a figure is rotated (around the origin) on the
coordinate plane, what happens to the original
coordinates (x and y) of its points?
The numbers “switch places” with every turn.
Look at the Quadrant to determine if and where
a negative sign is needed.

8. END OF LESSON