Is ABCD a rectangle

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Source: — Data Sufficiency |

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by daisy » Thu Jan 01, 2009 4:43 am
x = 90 means that all the inner angles will be of 90 degree. That means AD || BC and AB || CD. It also means that AD = BC and AB = CD.

Now the figure could be rectangle, if it satisfy the one more property of rectangle. That is, either AD>AB or AD<AB.

Now, since we don't know that whether AB = AD or AB > AB or AD < AB, therefore, statement 1 is insufficient.

Note: If AB = AD, then given figure would be a square, not a rectangle.

Statement 2: AB = CD

That means, BC = DA too. but then the figure may be Rhombus also as we don't know that values of the angles.

Hence, statement 2, insufficient

Taking both statements together,
Again the loop hole is still present, i.e., whether AB = AD or AB > AB or AD < AB. So, it cannot be confirmed that it is a square or rectangle.

Choose (E).

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Is ABCD a rectangle

by ifairo » Thu Jan 01, 2009 9:42 pm
Is rectangle not a square?

Based on my understanding about Geometry 101 (refer Just in time geometry by Catherine V. Jeremko, page # 125):
A square is-a rectangle is-a parallelogram is-a quadrilateral.
Also, A square is-a rhombus is-a parallelogram is-a quadrilateral.

If these relationships are true then the correct answer should be "A".

Am I wrong? Please help.

Regards.