Date: 10/3/95 at 17:28:29 From: Anonymous Subject: plane symmetry I am a first year b.ed. student and have to do a mathematics paper on plane symmetry and also a challenging activity related to this. The activity has to be appropriate for grades four to six. I have checked a lot of mathematics texts, but they fail to give me an in-depth understanding of this topic. Can you suggest a possible resource I could use, or do you have any suggestions for me? I would appreciate any help you can give me. Thanks.
Date: 10/9/95 at 20:31:6 From: Doctor Jonathan Subject: Re: plane symmetry Plane symmetry is analogous to line symmetry, except in three dimensions. For example, if the graph of an equation f(x,y,z)=g(x,y,z) has plane symmetry about the x-y plane, then the point (x,y,z) satisfies the equation if and only if (x,y,-z) does as well. As for a good way to illustrate this to students, you might want to use a mirror (which would be the plane of symmetry) and some simple objects. The image they see "through" the mirror has plane symmetry. You might want to ask the kids if they can think of everyday objects that exhibit plane symmetry and see if they can say where the reflecting plane is in each object. Some common objects with plane symmetry: spheres, boxes, swords, planes (that fly), humans (sort of). If the kids really aren't nterested, you could mention that handguns, swords and bombs have plane symmetry. You might ask them: How many planes of symmetry does a cube have? A sphere? Hope this helps. -Doctor Jonathan, The Geometry Forum
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