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Topic: Geometry Question #3
Replies: 39   Last Post: Jun 18, 2009 5:05 PM

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BHowitt@wlsv.org

Posts: 47
Registered: 9/11/06
RE: Geometry Question #3
Posted: Jun 17, 2009 2:36 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply
att1.html (4.9 K)

Because SED says so and that is the final answer. They are the all
knowing.

Beth Howitt
Math Department
Wellsville High School



"edward mertson" <emertson@nvcs.stier.org>
Sent by: owner-nyshsmath@mathforum.org
06/17/2009 01:59 PM
Please respond to
nyshsmath@mathforum.org


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Subject
RE: Geometry Question #3






And in the same line of reasoning, we?ve assumed that triangle ABC is
congruent to A?B?C? yet it isn?t marked as such in the question. So is
it even a rotation?
If the question is asking if there exists a transformation that will
produce image A?B?C?, and we must assume some basic common sense
conditions (such as the 2 triangles are congruent because they look
congruent, the triangles exist in the same plane, etc?) then, after
examining the diagram, is it reasonable for a student to also assume that
it appears that the that the image is a dilation with a factor of -1?
If not, why not?

From: owner-nyshsmath@mathforum.org [mailto:owner-nyshsmath@mathforum.org]
On Behalf Of George Reuter
Sent: Wednesday, June 17, 2009 8:12 AM
To: nyshsmath@mathforum.org
Subject: RE: Geometry Question #3

Hi all,

I'm just wondering... have we assumed that the rotation was 180 degrees?
If the rotation was 181 degrees or 179 degrees, then a dilation of factor
-1 is an incorrect choice.

The picture could be interpreted as a dilation, but it must be interpreted
as a rotation.

Regards,
George Reuter
Canandaigua Academy


Geometry Question #3: We had students identify the transformation as a
dilation (of -1). I called the State to see if they would allow credit if
a student chose choice #2 dilation. Their response: "No because there
are too many assumptions that must be made." And they wanted proof that a
rotation of 180 degrees is the same as a dilation of -1. Apparently this
is not common knowledge in the math world. Very frustrating.....very
frustrating.....



Ed Mertson

Newark Valley High School

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Date Subject Author
6/16/09
Read Geometry Question #3
edward mertson
6/17/09
Read Re: Geometry Question #3
Jonathan Halabi
6/17/09
Read RE: Geometry Question #3
Roberta Silver
6/17/09
Read RE: Geometry Question #3
reuterg@canandaiguaschools.org
6/17/09
Read RE: Geometry Question #3
edward mertson
6/17/09
Read RE: Geometry Question #3
reuterg@canandaiguaschools.org
6/17/09
Read RE: Geometry Question #3
edward mertson
6/17/09
Read RE: Geometry Question #3
BHowitt@wlsv.org
6/17/09
Read RE: Geometry Question #3
Tom Kenyon
6/17/09
Read Re: Geometry Question #3
Storey, Dolores
6/17/09
Read RE: Geometry Question #3
Roberta Silver
6/17/09
Read Re: Geometry Question #3
Storey, Dolores
6/17/09
Read Re: Geometry Question #3
reuterg@canandaiguaschools.org
6/17/09
Read Re: Geometry Question #3
Virginia Kuryla
6/17/09
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PJ Manzo
6/18/09
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cindy@wcs
6/17/09
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kgilbert@twcny.rr.com
6/18/09
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cindy@wcs
6/17/09
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ElizWaite@aol.com
6/17/09
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Jonathan Halabi
6/17/09
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Roberta Silver
6/17/09
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Storey, Dolores
6/17/09
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Tom Kenyon
6/17/09
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Kathy
6/17/09
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Tennantij@aol.com
6/17/09
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MathCaryl@aol.com
6/18/09
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ELEANOREVO@aol.com
6/18/09
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Sharon
6/18/09
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Eleanor Pupko
6/18/09
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Jonathan Halabi
6/18/09
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Sharon
6/18/09
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djud@optonline.net
6/18/09
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Tennantij@aol.com
6/18/09
Read non-regents geometry textbook
Brent Neeley
6/18/09
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Tennantij@aol.com
6/18/09
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Sharon
6/18/09
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Jonathan Halabi
6/18/09
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Sharon
6/18/09
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6/18/09
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