
RE: Geometry Question #3
Posted:
Jun 17, 2009 2:36 PM



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: ownernyshsmath@mathforum.org 06/17/2009 01:59 PM Please respond to nyshsmath@mathforum.org
To <nyshsmath@mathforum.org> cc
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: ownernyshsmath@mathforum.org [mailto:ownernyshsmath@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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