IM Geo.1.13 Lesson: Incorporating Rotations
The semaphore alphabet is a way to use flags to signal messages.
Here's how to signal the letters Z and J. For each, precisely describe a rotation that would take the left hand flag to the right hand flag.
- Rotate 90 degrees clockwise around .
- Rotate 180 degrees around .
- Rotate 120 degrees clockwise around .
- Rotate 60 degrees counterclockwise around .
Mai suspects triangle ABC is congruent to triangle DEF. She thinks these steps will work to show there is a rigid transformation from ABC to DEF.
Draw each image and determine the angle of rotation needed for these steps to take ABC to DEF.
Mai’s first 2 steps could be combined into a single rotation.
Find the center and angle of this rotation.
Describe a general procedure for finding a center of rotation.