2016­10­11 rotations .notebook
October 11, 2016
Today is Tuesday
10/11
Do Now:
-Take out notebook
-Copy down HW
Rotations Worksheet
Today's Objective: Rotations
2016­10­11 rotations .notebook
October 11, 2016
Transformation #3 ­ Rotation
A Rotationturnsa figureabout a fixedpoint
called thecenter of rotation
.
Center of Rotation­ point about which the figure is turned
(may be the origin or (0,0) on a graph)
**Rotation may be clockwise or counterclockwise...
if not stated assume counterclockwise.
With a rotation, the size and shape of the
pre-image is the same as the image.
Clockwise?
Counter-clockwise?
2016­10­11 rotations .notebook
October 11, 2016
Original Figure
90 degrees
90 degrees
clockwise
180 degrees
counter
clockwise
To rotate a figure:
1) Copy down the coordinates of the preimage
2) Rotate your page to see where the new figure should be
3) Write the points of the image after rotation
4) Plot the new image and label.
Rules:
90 Clockwise (x,y)--> (y,-x)
90 Counter Clockwise (x,y)--> (-y, x)
180 turn either way (x, y)--> (-x, -y)
2016­10­11 rotations .notebook
October 11, 2016
Turn the figure 90o clockwise
about the origin.
Record the points
A(
B(
C(
A
)
)
)
A' (
B' (
C' (
B
C
)
)
)
Turn the figure 90o clockwise
about the origin.
B
Record the points
A
A(
B(
C(
A' (
B' (
C' (
)
)
)
)
)
)
C
2016­10­11 rotations .notebook
October 11, 2016
Rotate the figure 180
counterclockwise about the
origin.
U
R
Record the points
R(
)
S(
)
U(
)
W(
)
R' (
S' (
U' (
W' (
S
)
)
)
)
What did you notice about the ordered pairs?
Turn the figure 90o counter - clockwise
about the origin.
Record the points
A(
B(
C(
)
)
)
A
A' (
B' (
C' (
)
)
)
W
C
B
2016­10­11 rotations .notebook
October 11, 2016
What do you notice when a figure is turned
180o?
What do you notice about the coordinates?
Attachments
Example_2__Rotations__or_Turn___Dragon_Falling 2 min.asf