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/ 
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Subject:  RE: More on What is a Trapezoid 
Author:  Annie 
Date:  Dec 13 2004 
> 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 K12 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.precollege newgroup, and is
summarized in this Dr. Math read:
http://mathforum.org/library/drmath/view/54901.html
Annie
 
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