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Topic: trapezoid clarification
Replies: 55   Last Post: Apr 24, 2017 2:30 PM

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 barrpub Posts: 7 From: Hauppauge, NY Registered: 2/13/14
RE: trapezoid clarification
Posted: May 18, 2014 10:33 AM
 att1.html (7.9 K)

Doesn't a parallelogram have opposite parallel sides with the parallel sides the same length?

________________________________
From: owner-nyshsmath@mathforum.org <owner-nyshsmath@mathforum.org> on behalf of mvanetten@moraviaschool.org <mvanetten@moraviaschool.org>
Sent: Sunday, May 18, 2014 8:12 AM
To: nyshsmath@mathforum.org
Subject: Re: trapezoid clarification

Yes. A parallelogram is a trapezoid. I would like to see the clarifications but until they come we might want to look to earlier grades where they are defining these shapes. They have a venom diagram in the 5 th grade modules that show parallelograms are trapezoids.
Michelle

Sent from my iPhone

On May 17, 2014, at 4:25 PM, JFish@csufsd.org<mailto:JFish@csufsd.org> wrote:

So are you claiming that a parallelogram IS a trapezoid??????????

Jim

-----owner-nyshsmath@mathforum.org<mailto:owner-nyshsmath@mathforum.org> wrote: -----
To: "<nyshsmath@mathforum.org<mailto:nyshsmath@mathforum.org>>" <nyshsmath@mathforum.org<mailto:nyshsmath@mathforum.org>>
From: Gene Jordan
Sent by: owner-nyshsmath@mathforum.org<mailto:owner-nyshsmath@mathforum.org>
Date: 05/17/2014 04:11PM
Subject: Re: trapezoid clarification

Here's the chart.
[image.png]
I thought there was a trapezoid thread earlier, the geometry standards clarification document has it there. It should be released soon.

[image.jpeg]

I think Euclid defined Trapezoia as "all other quads". I tweeted the above image with the hope the end of the trapezoid wars was near. I remain neutral on inclusive or exclusive superiority, but would always appreciate our continued request for releasing a CCLS glossary to help us with precise language.
Sorry for my brevity ( and imprecision) it's a cool yet beautiful day to be outside.

~Gene Jordan

Broome County AMTNYS chair (Southern Tier)

On May 17, 2014, at 8:35 AM, "Meg Clemens" <mclemens@twcny.rr.com<mailto:mclemens@twcny.rr.com>> wrote:

At training in Albany this past week, NYSED released a standards clarification document for Geometry that states (among other items) that a trapezoid is now defined with the 'inclusion' definition: a trapezoid has at least one pair of parallel sides. Although this might be a surprise to NYS teachers who have used the exclusive definition, this is a common definition for trapezoid.

Three questions:

1. Is this standards clarification memo posted on engageny anywhere yet? I couldn't find it.

2. How do we treat conflicting definitions next year when we are preparing students for both regents?

3. With the new definition, what is an isosceles trapezoid? I think we need clarification on this.

a. If I use trapezoid w/ one pair of opposite sides congruent, then a parallelogram is an isosceles trapezoid but its base angles are not congruent.

b. If I use trapezoid w/ one pair of opposite sides congruent and base angles are congruent, then rectangles and squares are isosceles trapezoids, which might be OK.

c. There is an alternative definition that uses one axis of symmetry and one w/ no symmetry to yield the usual depiction of an isosceles trapezoid.

Meg Clemens
Canton Central School
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