Using the Classroom
as a Coordinate Grid for Transformations
Topic Index | Geometry Index | Regents Exam Prep Center

Using colored electrical tape, draw a set of coordinate axes (on the floor) down the center of your classroom, dividing the students' desks into four quadrants.  (Avoid using masking tape as it is difficult to remove from the floor once students have walked on it.)  Establish where the positive x-axis and the positive y-axis are located.

The students can now be asked to identify "who" is their:

1. reflection over the x-axis.
2. reflection over the y-axis.
3. point reflection in the origin.
4. translation under a given pattern.

Questions can be posed in various ways:

  • a straightforward manner, such as:
    "Which student is your reflection over the x-axis?"

  • an indirect manner, such as:
    "Susan is someone's point reflection in the origin.  Who is that person?"

  • an inquisitive manner, such as:
    "Pick any student in the room.  Using your knowledge of transformations, tell me how you could be "transformed" to that student's position."
    (Teacher demonstrates by giving an example.)

Be sure to call on all students during the activity.  Questions can be directed at specific students or the entire class. It is possible to engage all students without embarrassing any one pupil.  Directing questions to the entire class at the beginning of the activity may give the slower student time to process how the activity will work and allow him/her to orient himself/herself with the grid of desks.  Students should, however, realize that they WILL be expected to participate in the activity.

Written responses are also possible - but the oral aspect of this activity is its charm.