Math A

Folding Activities
with Reflections

 

In each of the following three folding activities, the objective is to reinforce the concept of line reflections.  An important element of the exercises is to emphasize that the distance from a point to the line of reflection is equal to the distance from the point's image to the line of reflection.  Encourage students to measure to verify this concept.

1.  Dark Imprint Folding 

Fold a sheet of paper.  Draw a polygon using a dark colored marker.  Turn the paper over and trace the image of the polygon as seen through the paper.   Open the paper to reveal both the object and its reflection.  Use a ruler to measure the distances from the vertices of the polygon (and its image) to the line of reflection.

 

2.  Food Coloring Folding

Fold a sheet of paper (or graph paper).  Open the paper and place several drops of food coloring on one side of the fold.  Fold the paper allowing the food coloring to smear onto the other side of the page.  Find distinguishing features on several of the "blobs".  Have students measure distances to the line of reflection from these features and their images.

 

3.  Image Imprint Folding 

Choose an object which has distinct edges, such as a key.  Place the object between a folded sheet of paper.  Massage the image through the paper being particularly careful to outline the edges.  Open the paper and view the imprint of the object.  Have students measure from a position on the object (and on its image) to the line of reflection.

 

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Roberts