The left side of a human face is close to being the mirror image of the right side - but not exactly.  The first photo (in each section below) is the original photograph of the individual.  The second and third photographs are composite pictures made by merging each side of the first picture with its corresponding reflection.

If the vertical line (line of symmetry) is drawn through the center of each of the composite pictures, each point of the picture on one side of the line has an image point in the other side.  The composite pictures are symmetric with respect to this vertical line.

Activity:

• Using a digital camera, take photographs of the students in your class.  Try to get the students to look directly at the camera and to avoid tilting their heads.  This is not always easy to do.  Smiles!

• Using a drawing program, such as Paint Shop Pro, create composite drawings such as those shown above.
  For Paint Shop Pro: (1) use your selection tool to outline one side of the photo, (2) under Image, choose Mirror, (3) drag the new image so it will create a new face, (4) crop your new image, and (5) save the photo.  Repeat the process for the other side of the face.

• Print the three photos to be given to the students.

This activity will take some time to prepare.  Your efforts, however, will be very well received by the students (and their parents).

My students were amazed at their new images and giggled and laughed appropriately.  Teachers from other subject areas approached me the day of this activity to explain that the students were showing the photos to their other teachers.  When I asked if the students could explain what had gone on in the photos, I heard responses such as " yes, I heard the whole story about line symmetry."  Bingo!  Mission accomplished.