| Discussion: | Dynamic Geometry Exploration: Properties of the Midsegment of a Trapezoid tool |
| Topic: | Midsegment of a rectangle? |
| Related Item: | http://mathforum.org/mathtools/tool/15621/ |
| Post a new topic to the Dynamic Geometry Exploration: Properties of the Midsegment of a Trapezoid tool Discussion discussion |
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| Subject: | RE: More on What is a Trapezoid |
| Author: | Annie |
| Date: | Dec 13 2004 |
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> I suppose it is legal to respond to your own post. :-)
I'd like
> to hear more about the original discussion that I was trying to
> generate here.
Consider these two definitions:
Def 1 A
> quadrilateral with at least one pair of parallel sides.
Def 2 A
> quadrilateral with EXACTLY one pair of parallel sides.
I think
> most US high school text books define a trapezoid with definition 2.
> Does anyone know of a US high school textbook that doesn' t define
> trapezoids in that way (or equivalant to that)? Does anyone know the
> history of when or why that definition came to be used in schools,
> at least in the US? Is definition 1 used in other countries in
> current K-12 textbooks?
As far as I know, the UCSMP books use the more inclusive definition. I don't
know of other high school textbooks that use it (I was holding out for Jacobs,
but he didn't come through for me). The topic of the defintion has been
discussed a bit on the Forum's geometry.pre-college newgroup, and is
summarized in this Dr. Math read:
http://mathforum.org/library/drmath/view/54901.html
-Annie
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