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anonymous

  • one year ago

ABCD is a parallelogram. What information would NOT allow you to conclude that ABCD is a rectangle? http://i1286.photobucket.com/albums/a605/kristinalucy/EXAM1_zpsedxurx2v.png

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  1. anonymous
    • one year ago
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    it would be the angle DAB=90 degrees.

  2. anonymous
    • one year ago
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    @MathGuyThatWantsHelp But I thought rectangles have 4 right angles? I'm trying to find the answer on how not to conclude that its a rectangle..

  3. anonymous
    • one year ago
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    its either the first answer or the fourth answer because it only has 3 points not telling us if there is any more than just 3

  4. anonymous
    • one year ago
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    @MathGuyThatWantsHelp I don't understand what you mean.....I thought at first it was the third because rectangles don't have 4 equal sides?

  5. anonymous
    • one year ago
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    ***I thought it was the third answer

  6. anonymous
    • one year ago
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    the measurements can be different with the third answer it doesn't say that all the sides are equal. I read it carefully and the best answer i can think of is the first one.

  7. anonymous
    • one year ago
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    Okay thank you! @MathGuyThatWantsHelp

  8. mathstudent55
    • one year ago
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    Answer D is not it. A parallelogram has two pairs of congruent opposite angles. If only one angle is known to be a right angle, then the angle opposite that angle is also a right angle. Those two opposite angles add up to 180 degrees. There are 180 degrees left for the other two angle, but since they are congruent, they measure 90 degrees each, so all angles are right angles and it's a rectangle.

  9. mathstudent55
    • one year ago
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    Answer B is also not it. If a parallelogram has congruent diagonals, then it is a rectangle.

  10. mathstudent55
    • one year ago
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    Answer A is also not it. The diagonals of a parallelogram bisect each other. The diagonals of a rectangle are congruent. If those two half diagonals are congruent, then the diagonals are congruent and this parallelogram is a rectangle.

  11. mathstudent55
    • one year ago
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    That leaves only choice C. If each pair of adjacent sides of a parallelogram is congruent, then that makes the parallelogram a rhombus, but it does not make it a rectangle.

  12. anonymous
    • one year ago
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    Thank you so much! I understand it now!! Thank you @mathstudent55

  13. anonymous
    • one year ago
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    @mathstudent55 could you help me with another question please?

  14. mathstudent55
    • one year ago
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    You're welcome.

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