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

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 Meg Clemens Posts: 345 Registered: 12/3/04
trapezoid clarification
Posted: May 17, 2014 8:31 AM
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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