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Topic: Trapezoid definition
Replies: 26   Last Post: Oct 7, 2004 11:51 PM

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Mary Krimmel

Posts: 629
Registered: 12/3/04
Re: Is a rectangle a square?
Posted: Sep 28, 2004 4:52 PM
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At 04:09 PM 9/28/04 -0400, you wrote:
. . .
. . .
>Professor Conway, on the other hand, defines a trapezoid as a
>quadrilateral with "at least" on pair of parallel sides. Using that
>definition, the set of parallelograms is clearly a subset of the set
>of trapezoids. Thus, using that definition, every rectangle is a
>trapezoid, and also a parallelogram (as is the case with the usual
>A similar problem exists with the definition of the kite. Most
>writers say it is a quadrilateral in which AT MOST one diagonal is the
>perpendicular bisector of the other. Conway would say that it is a
>quadrilateral in which AT LEAST one diagonal is the perpendicular
>bisector of the other. So using Conway's definition, every rhombus is
>a kite.
>There have been many, many message threads here on this issue.
>Logically, there is a great deal to be said for Prof. Conway's

Amen. Most of the other conflicting definitions defy logic.

Mary Krimmel

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