Talk:Trapezoid

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Note that a trapezium (British English) or trapezoid (American English) does not have two parallel sides. What kind of beast is a (U.S.)trapezium ? --FvdP 19:37, 12 Mar 2004 (UTC)

A USA Trapezium is what the rest of the world calls trapezoid (no sides parallel). For whatever reason the Americans swapped the name. — Jor (Talk) 19:20, 1 Apr 2004 (UTC)
    The matter is utterly confusing. At the top of the page a trapezoid has two parallel sides. At the bottom said four sided figure has no tow sides parallel. Querobert August 21 2004

In the United States, a trapezoid has two parallel sides. — 131.230.133.185 10:30, 3 August 2005 (UTC)

Contents

[edit] The school definition of T.

"A quadrilateral that has exactly two sides parallel." (bold is mine - GS), see f.e. http://www.math.com/school/glossary/defs/trapezoid.html.

I hate the definition because 1) I used to think a parallelogram is a trapezoid and 2) I know about open sets and closed sets and I beleve a practical definition should define a closed set, not an open one.

So my question to contributors: did you mean "exactly two sides parallel" or "at least two sides parallel"? and what should we do with all that? --GS 14:34, 18 Apr 2005 (UTC)

Indeed, in grade school (at least in Ontario, Canada), students are being taught that a trapezoid must have exactly two parallel sides; i.e., a parallelogram is not a trapezoid. This is inconsistent with other definitions that I have seen, so there certainly seems to be some controversy over the matter. In fact, the exactly-two-parallel-side definition seems to be the most prevalent (however silly that definition seems to me), so this Wikipedia article should probably be updated to at least mention this definition. --Pomakis 17:18, 29 January 2006 (UTC)

It means "at least" two sides parallel, to fit in the diagram which includes all quadrilaterals. "all Parallelograms are Trapeziums, all Trapeziums are Quadrilaterals" "some Quadrilaterals are Squares, all Squares are Parallelograms, which in turn, makes them Trapeziums" --Rkeysone 14 September 2006

[edit] Area

How come the area is (L1+L2)/2×H

Split the T. to two triangles, calculate and sum. What is your answer, anyway? --GS 14:18, 26 Apr 2005 (UTC)

[edit] Absolutely Merge it

goldenrowley 8-6-06

[edit] Different types of trapazoids

Requested: add different type of trapazoids. ex: isosceles trapazoid

Well, isoceles trapezoid is already discussed, what others do you have in mind? In either case, be bold! -- Meni Rosenfeld (talk) 16:30, 13 December 2006 (UTC)

[edit] Definition of 'Midsegment'

Requested: please account for the definition of a midsegment in the case of parallelograms. The currently used definition of a trapezoid (i.e. a shape with two parallel sides) allows for the inclusion of parallelogram, which is fine. However, the definition of a midsegment then states that the midsegment is to be drawn from the midpoints of the non-parallel sides, which a parallelogram does not have. So, either a parallelogram doesn't have a midsegment (this, I think, is not the correct solution) or the definition of a trapezoid needs to be more restrictive to not include parallelograms (not everyone would be happy with that) or, and this is likely the best solution, the definition of a midsegment of a trapezoid needs to be modified to account for the case of parallelograms.

I've made a modification which aspires to solve this issue. -- Meni Rosenfeld (talk) 16:30, 13 December 2006 (UTC)