9-4: Rotations Objectives: Assignment: To perform rotations

9-4: Rotations
Objectives:
1. To perform rotations
Assignment:
• P. 127-128: 5-15
• Challenge Problems
Objective 1
You will be able to
perform rotations
Reflection
A rotation is rigid
motion that maps turns
a figure according to a
an angle of rotation
and a center of
rotation.
The original figure is
called the pre-image
Center of rotation
The transformed figure
is called the image
Investigation: Rotations
1. Open your GSP
file. On the first
tab, drag point 𝐶
on the angle of
rotation and
observe the
relationship
between the image
and the pre-image.
Investigation: Rotations
2. Now drag point
the point marked
Center of
Rotation and
observe the
relationship
between the
image and the
pre-image.
Investigation: Rotations
3. Next, click on the
Rotations tab at
the bottom of the
screen. Click on
the Rotate 90
button.
Investigation: Rotations
4. Drag points on
the pre-image.
Observe the
corresponding
points on the
image.
Investigation: Rotations
5. Click on the
Perpendicular
Segments button.
What do you
notice about
these segments
and their
endpoints? What
is the center of rotation?
Investigation: Rotations
6. Let 𝑥, 𝑦 be a
point on the preimage. Write a
coordinate
mapping that
rotates this point
90° around the
origin.
Investigation: Rotations
7. Repeat Steps 3-6
for a rotation
around the origin
for 180°, 270°,
and 360°.
Transformation Coordinate Rules
Coordinate Notation for a Rotation
Presentation: Rotations
Now complete the SpringBoard activities on
P. 120-122 and P. 124.
As a group, create a presentation that
summarizes what you’ve learned about
translations. Also decide who in your group
will teach this information to the rest of the
class.
9-4: Rotations
Objectives:
1. To perform rotations
Assignment:
• P. 127-128: 5-15
• Challenge Problems