Quadrilateral Classification: Definition of a Trapezoid
Date: 01/15/97 at 13:45:54 From: Anonymous Subject: Trapezoid ? Dr. Math, What is the correct definition for a trapezoid? And why? My questions come from the Math Department at Carroll Middle School in SouthLake, Texas. Two of the math teachers have found well-known publications with very different definitions for a Trapezoid. 1) Trapezoid: Quadrilateral with at least 1 pair of sides parallel. 2) Trapezoid: A trapezoid is a quadrilateral with exactly one pair of parallel sides. Can you help? Thanks. - Craig C.
Date: 01/15/97 at 15:48:19 From: Doctor Steve Subject: Re: Trapezoid ? Hello Craig, This has actually been discussed quite thoroughly by professionals on our geometry newsgroups. You can search for these discussions by going to http://mathforum.org/kb/forum.jspa?forumID=128 and searching for the word trapezoid . In the list of found discussions you'll see three that most relate: Definition of a trapezoid, Classification of Quadilaterals, and Defining Quadilaterals. The bottom line is that these professionals are most comfortable with a definition like the first one you offer. Here is a classification scheme that reflects the first definition, found in "A Problem Solving Approach to Mathematics for Elementary School Teachers" by Billstein et al. Quadrilateral / \ / \ Kite Trapezoid | / \ | / \ | Parallelogram Isosceles | / \ Trapezoid | / \ / \ / \ / Rhombus Rectangle \ / \ / \ / Square taken from article by Tad Watanabe in thread http://mathforum.org/kb/message.jspa?messageID=1076714 -Doctor Steve, The Math Forum Check out our web site! http://mathforum.org/dr.math/
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