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If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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16 Jul 2012, 03:56
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Re: If p is the perimeter of rectangle 0, what is the value of p [#permalink]
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16 Jul 2012, 10:00
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Let x and y be two sides of the rectangle.. then p =x+y Stat1 Diagonal = 10 => x^2 + y^2 = 10^2 we cannot find p i.e. x+y using this info so NOT SUFFICIENT Sta2 Area = 48 => xy =48 we cannot find p i.e. x+y using this info so NOT SUFFICIENT Combining (1) and (2) we will get value of x+y = sqrt (x+y)^2 = sqrt(x^2 + y^2 + 2xy) = sqrt ( 10^2 + 2*48) sqrt(196) = 14 SUFFICIENT So, answer will be C
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Re: If p is the perimeter of rectangle 0, what is the value of p [#permalink]
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20 Jul 2012, 03:40
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Re: If p is the perimeter of rectangle 0, what is the value of p [#permalink]
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28 Jul 2012, 14:42
If instead, Q were a square, would 1 be sufficient?
In a rectangle, why can't we use the Isosceles Triangle to figure out the third side since the diagonals bisect each other?



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Re: If p is the perimeter of rectangle 0, what is the value of p [#permalink]
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29 Jul 2012, 00:36



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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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12 Dec 2012, 13:40
I'm sorry I'm still not seeing how this is not answer "A". I understand the logic at arriving at answer "C", I just don't understand why you NEED to combine statements "1" and "2", contradicts my entire understanding of Data Sufficiency logic.
A rectangle is comprised of 4 right angles, no?
So ultimately the "diagonal" represents the hypotenuse forming two right triangles, no?
Can you form a right triangle with a hypotenuse of 10 with any other legs besides 6 and 8? Or do I have that wrong?
(pythagorean triplet (3, 4, 5) , (6, 8, 10))



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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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13 Dec 2012, 02:21
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kelleygrad05 wrote: I'm sorry I'm still not seeing how this is not answer "A". I understand the logic at arriving at answer "C", I just don't understand why you NEED to combine statements "1" and "2", contradicts my entire understanding of Data Sufficiency logic.
A rectangle is comprised of 4 right angles, no?
So ultimately the "diagonal" represents the hypotenuse forming two right triangles, no?
Can you form a right triangle with a hypotenuse of 10 with any other legs besides 6 and 8? Or do I have that wrong?
(pythagorean triplet (3, 4, 5) , (6, 8, 10)) Hi Kellygrad05, There was a similar problem I was attempting yesterday on the forum. Basically we are told that it is a rectangle but we aren't sure if the sides are Integers or not. For ex. Diagonal10, sides can be 6 and 8 (because of PT) or something like Square root 99 and 1...and such other combination When you consider the st2 with above then we can figure out sides will be 6 and 8 as only in that condition Area will be 48 and Diagonal as 10. Thanks
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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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13 Dec 2012, 03:18
kelleygrad05 wrote: I'm sorry I'm still not seeing how this is not answer "A". I understand the logic at arriving at answer "C", I just don't understand why you NEED to combine statements "1" and "2", contradicts my entire understanding of Data Sufficiency logic.
A rectangle is comprised of 4 right angles, no?
So ultimately the "diagonal" represents the hypotenuse forming two right triangles, no?
Can you form a right triangle with a hypotenuse of 10 with any other legs besides 6 and 8? Or do I have that wrong?
(pythagorean triplet (3, 4, 5) , (6, 8, 10)) A right triangle with hypotenuse 10, doesn't mean that we have (6, 8, 10) right triangle. If we are told that the lengths of all sides are integers, then yes: the only integer solution for right triangle with hypotenuse 10 would be (6, 8, 10). To check this: consider the right triangle with hypotenuse 10 inscribed in circle. We know that a right triangle inscribed in a circle must have its hypotenuse as the diameter of the circle. The reverse is also true: if the diameter of the circle is also the triangle’s side, then that triangle is a right triangle. So ANY point on circumference of a circle with diameter of 10 would make the right triangle with diameter. Not necessarily sides to be 6 and 8. For example we can have isosceles right triangle, which would be 454590: and the sides would be \(\frac{10}{\sqrt{2}}\). OR if we have 306090 triangle and hypotenuse is \(10\), sides would be \(5\) and \(5*\sqrt{3}\). Of course there could be many other combinations. Similar questions to practice: ifthediagonalofrectanglezisdandtheperimeterof104205.htmlwhatistheareaofrectangularregionr105414.htmlwhatistheperimeterofrectangler96381.htmlHope it helps.
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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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13 Dec 2012, 07:37
Thank you Bunuel, it's clear my understanding of pythagorean triplets was incomplete. The example of the triangle within the circle was quite illuminating. So to summarize, if it is given that all sides of the triangle are integers, and the hypotenuse was given, only then I could have deduced it was part of a pythagorean triple, correct? Was that my only misstep at arriving at answer "A"?



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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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13 Dec 2012, 07:43



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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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17 Dec 2013, 11:07
Bunuel wrote: If p is the perimeter of rectangle Q, what is the value of p? (1) Each diagonal of rectangle Q has length 10. (2) The area of rectangle Q is 48. Diagnostic Test Question: 48 Page: 26 Difficulty: 650 1) Basically, in saying that the diagonal is 10, they are giving us the hypotenuse of a right triangle. There is no info about the two other sides though, so insufficient. 2) They are simply telling us the area, which is not enough for us to know the perimeter since there are many different products of two that can yield 48. However, taking 1 and 2 together, they are giving us the hypothenuse (in 1) and the RELATION between the two other sides of the triangle (in statement 2). Since the pythagoran theorem restricts which size two sides can have, if we are given the third (hypothenuse), then this relation between the other two sides is enough. Notice that I did not do any calculation at all. The DS questions are more about "does this make sense?" than they are about testing if exact boundaries and relations hold up.



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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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09 Jan 2014, 10:26
Bunuel wrote: If p is the perimeter of rectangle Q, what is the value of p? (1) Each diagonal of rectangle Q has length 10. (2) The area of rectangle Q is 48. Diagnostic Test Question: 48 Page: 26 Difficulty: 650 Please, correct me if Im wrong because I really need to make sure my "process" is correct: Statement one tells us that: (length)^2 + (width)^2 = 100 Statement two tells us that: (length)*(width) = 48 Obviously, the two statements alone are not sufficient.. So it's between C and E. Basically, we are given two equations and two unknowns, so we can solve for both X and Y, and thus we can solve for 2x + 2y = p. That's why C is correct. Bunuel, is this process valid?



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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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18 Mar 2015, 20:46
I'm was baffled at how the answer wasn't A as well, since when applying the 306090 x, \sqrt{3} , and 2x you could technically get the other sides. We know the hypotenuse is 10, so we have 2x = 10, so x would be 5 and the last side would be 5\sqrt{3}...
But the second statement contradicts this I guess... something to look out for! I thought I was being clever applying that concept.



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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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16 May 2015, 07:54
Hi,
I am surprised as well that A was not the correct answer but not for the reasons explained in the previous posts (except if I missed something).
The question is stating that we have a rectangle to consider.
1) tells us that each diagonal of rectangle Q has length 10.
I would guess a rectangle that has its diagonals equal is always a square. If this is a square then knowing the hypotenuse (the diagonal) is enough to guess the perimeter.
Anyone to help me on this? Thanks



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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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16 May 2015, 08:10



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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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16 May 2015, 08:29
Bunuel wrote: tsunagaru wrote: Hi,
I am surprised as well that A was not the correct answer but not for the reasons explained in the previous posts (except if I missed something).
The question is stating that we have a rectangle to consider.
1) tells us that each diagonal of rectangle Q has length 10.
I would guess a rectangle that has its diagonals equal is always a square. If this is a square then knowing the hypotenuse (the diagonal) is enough to guess the perimeter.
Anyone to help me on this? Thanks The diagonals of a rectangle are always equal. Indeed... I have been a bit quick in my guess. Thanks a lot!



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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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21 Jul 2015, 14:05
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I did not use the math way this is how I did it
it is given that 2L +2w= the perimeter of a rectangle 1. each diagnal of a rectangle is length of 10 which makes the rectangle in half so it cant, but just know the triangle height = not sufficient 2. the area of a rectangle is 48 so l*w= area not sufficent
both will tell us 2 equations and can find the length an width to get p so it is C thanks



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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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04 Aug 2015, 12:17
While solving this problem , I thought that the diagonal must split the rectangle in 2 Triangles 30,60,90°  But then found this rule A diagonal splits a rectangle into two congruent 306090 triangles, if, and only if, the diagonal is twice as long as the width of the rectangleMay be it helps some of you.
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Re: If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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04 Aug 2015, 13:01
BrainLab wrote: While solving this problem , I thought that the diagonal must split the rectangle in 2 Triangles 30,60,90°  But then found this rule A diagonal splits a rectangle into two congruent 306090 triangles, if, and only if, the diagonal is twice as long as the width of the rectangle May be it helps some of you. A quick way to remember this is to know that all squares are rectangles but not all rectangles are square. Additionally, diagonals of a square bisect the 90 degree angles. Thus the 2 triangles formed by any 1 of the diagonals has angles 454590. So this shows that the rectangle can have different angles and not just 306090 or 454590. The actual values will depend upon the values of either one of l or b or length of the diagonal (we will need 2 of them).



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If p is the perimeter of rectangle Q, what is the value of p [#permalink]
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04 Aug 2015, 13:15
Thanks Engr2012. I have already repeated my Geometry script.. Actually we can be just sure that we have a right triangle, but other information cannot be deducted from the statement (as 30,60,90°), and as you said we have only more information about a diagonal of a square.
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