- Students write a matrix and show all matrix multiplication.
- Then the students draw in the new quadrilateral on the coordinate grid.
- Finally, have students exchange papers and complete a peer check.
- Each person needs to check the other person’s work.
- Allow time for the students to share their reflections in small groups when finished.
III.MeetingObjectives
- Students will find the reflection of a point in a line on a coordinate plane.
- Students will multiple matrices.
- Students will apply matrix multiplication to reflections.
- Students will verify that a reflection is an isometry.
- Students will use what they have learned to draw a reflection of a quadrilateral.
- Students will demonstrate understanding by explaining their work in small groups.
IV.NotesonAssessment
- Walk around and observe students as they work.
- Which strategies are the students using?
- Listen in on small group discussions.
- Is the student understanding lines of reflection?
- Offer assistance/feedback as needed.
Rotations
I.SectionObjectives
- Find the image of a point in a rotation in a coordinate plane.
- Recognize that a rotation is an isometry.
- Apply matrix multiplication to rotations.
II.ProblemSolvingActivity-RotatingTriangles
- For this problem, the students need to practice drawing rotations using matrices.
- Students will need graph paper, rulers and colored pencils.
- Tell students to use color to show the different rotations that they are going to be drawing on the coordinate
grid. - First, have the students draw a triangle on the coordinate grid.
- Then ask the students to write a matrix to describe this triangle.
- Next, they use matrix multiplication to rotate the triangle 180◦.
- Finally, they draw in the triangle.
- Then using the same original triangle, students are going to use matrix multiplication to rotate a triangle 90◦.
- After multiplying, they draw in the triangle.
- When finished, have students exchange papers so that a peer can check their work.
- Staple the work sheet with the matrix multiplication to the back of the sheet with the coordinate grid drawings.
III.MeetingObjectives
- Students will find the image of a point in a rotation in a coordinate plane.
Chapter 5. Geometry TE - Problem Solving