Translations, Reflections, Rotations
This lesson will allow students to explore translations, reflections, and rotations using a resource of Shodor Education Foundation, Inc. Permission has been granted for the use of the materials as part of the workshop Interactivate Your Math Students. Students explore the world of translations, reflections, and rotations in the Cartesian coordinate system by transforming squares, triangles and parallelograms. Parameters: Shape, x or y translation, x or y reflection, angle of rotation. (Italics are a direct quote from Shodor.org.)
A lesson plan for grades 6–8 Mathematics
Learning outcomes
Upon completion of this lesson, students will:
- have been introduced to the concepts of translation, reflection, and rotation.
- have practiced translating, reflecting, and rotating two-dimensional objects on the coordinate plane.
Teacher planning
Time required for lesson
50 Minutes
Materials/resources
graph paper
construction paper
glue
markers
Technology resources
computer with Internet access
one computer for each pair of students
Pre-activities
Students should be able to graph and locate points using ordered pair and understand the concept of symmetry.
Prior to teaching the lesson students need to
- Create a coordinate plane on graph paper - label the x and y axis 0 - 12 - label the 4 quadrants.
- Using construction paper, cut out 4 identical 6 cm squares. Color each angle a different color. (This simulates the transmographer activity on the Interactivate website.)
Activities
Discussion of the meaning of translations, reflections, and rotations. (An excellent example can be found on the Interactivate website.)
Guided Practice - Students access the Interactivate Transmographer. Teacher walks the students through at least two simulations in each category - translations, reflections, rotations.
Independent Practice - Students explore the activities in pairs. Students use the previously created graphs and squares to model rotations around the y axis beginning in quadrant 1
- Paste a square in quadrant 1 and label the x and y coordinates of each corner - the students select the coordinates
- The students select a second square to show the location of the original square when rotated 90 degrees - paste the square in the new position and label the coordinates of the corners
- Select a third square to model a 180 degree rotation from the original position
- Select the final square to model a 270 degree rotation from the original position
Students should be encouraged to refer to the computer activity for assistance.
Assessment
Use each student’s graph:
Mastery 3 out of 4 rotations with appropriate labeling of ordered pairs
Understanding 2 out of 4 rotations with labeling of ordered pairs
Needs Practice 1 out of 4 rotations
Websites
Activities
Discussion
Comments
This lesson was written in an attempt to address the issue of learning differences. The concepts can be very difficult for students with learning disabilities. Using the computer simulation as well as the construction model can be very effective.
North Carolina Curriculum Alignment
Mathematics (2004)
Grade 6
- Goal 3: Geometry -The learner will understand and use properties and relationships of geometric figures in the coordinate plane.
- Objective 3.03: Transform figures in the coordinate plane and describe the transformation.
- Objective 3.04: Solve problems involving geometric figures in the coordinate plane.
Grade 7
- Goal 3: Geometry - The learner will understand and use properties and relationships in geometry.
- Objective 3.02: Identify, define, and describe similar and congruent polygons with respect to angle measures, length of sides, and proportionality of sides.
- Objective 3.03: Use scaling and proportional reasoning to solve problems related to similar and congruent polygons.
Grade 8
- Goal 3: Geometry - The learner will understand and use properties and relationships in geometry.
- Objective 3.01: Represent problem situations with geometric models.
- Objective 3.03: Identify, predict, and describe dilations in the coordinate plane.



