Author 
Message 
TAGS:

Hide Tags

Intern
Joined: 29 Sep 2009
Posts: 12

What is the area of parallelogram ABCD ? [#permalink]
Show Tags
05 Apr 2011, 14:41
1
This post received KUDOS
2
This post was BOOKMARKED
Question Stats:
48% (00:49) correct 52% (00:44) wrong based on 233 sessions
HideShow timer Statistics
What is the area of parallelogram ABCD ? (1) AB = BC = CD = DA = 1 (2) AC = BD = \(\sqrt{2}\) (C) 2008 GMAT Club  M1305
Official Answer and Stats are available only to registered users. Register/ Login.



Math Forum Moderator
Joined: 20 Dec 2010
Posts: 1945

Re: geometry, data sufficiency [#permalink]
Show Tags
05 Apr 2011, 15:28
2
This post received KUDOS
1
This post was BOOKMARKED
Knesl wrote: What is the area of parallelogram \(ABCD\) ?
1. \(AB = BC = CD = DA = 1\) 2. \(AC = BD = \sqrt{2}\)
(C) 2008 GMAT Club  s10#1
* Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient * Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient * BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient * EACH statement ALONE is sufficient * Statements (1) and (2) TOGETHER are NOT sufficient
why is statement 2 not sufficient? when the two diagonals are to be the same then it is possible only in case of square. Therefore, the sides are defined as well. Or am I wrong? 1. Can be square or rhombus. 2. Diagonals are same for rectangle and square. For square the area will be: Area = 1*1 as the side will be 1. Diagonal is \(sqrt{2}\), Diagonal=hypotenuse of 459045 right triangle. Side= 1. For rectangle the sides can be: 0.5, 1.12; Area = 0.56 OR 0.75, 1.2; Area = 0.9 Basically, all combination of l and w that satisfies: l^2+w^2=2. And there are infinite such possibilities. Combining; We know it's a square and area is 1. Ans: "C"
_________________
~fluke
GMAT Club Premium Membership  big benefits and savings



TOEFL Forum Moderator
Joined: 16 Nov 2010
Posts: 1590
Location: United States (IN)
Concentration: Strategy, Technology

Re: geometry, data sufficiency [#permalink]
Show Tags
05 Apr 2011, 16:50
The answer is C as fluke has explained. To add a bit more, it were a square then there is no need to calculate the sides, the area can be simply 1/2 * d1 * d2.
_________________
Formula of Life > Achievement/Potential = k * Happiness (where k is a constant)
GMAT Club Premium Membership  big benefits and savings



Manager
Joined: 14 Jun 2011
Posts: 84

Re: What is the area of parallelogram ABCD ? 1. AB = BC = CD = [#permalink]
Show Tags
19 Mar 2014, 10:43
1
This post received KUDOS
I have a doubt in the explanation of this question. The official ans says that all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus but this is the property of square(a parallelogram) as well...?\
_________________
Kudos always encourages me



Math Expert
Joined: 02 Sep 2009
Posts: 43887

What is the area of parallelogram ABCD ? [#permalink]
Show Tags
20 Mar 2014, 00:56
2
This post received KUDOS
Expert's post
1
This post was BOOKMARKED
swati007 wrote: I have a doubt in the explanation of this question. The official ans says that all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus but this is the property of square(a parallelogram) as well...?
Yes, both a rhombus and a square have equal sides. From (1) we know that ABCD is a rhombus. A square is a special type of a rhombus, so from (1) ABCD is a rhombus and can be a square. What is the area of parallelogram \(ABCD\)?Notice that we are told that ABCD is a parallelogram. (1) \(AB = BC =CD = DA = 1\) > all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus. Area of a rhombus equals to \(\frac{d_1*d_2}{2}\) (where \(d_1\) and \(d_2\) are the lengths of the diagonals) or \(bh\) (where \(b\) is the length of the base and \(h\) is the altitude), so we don't have enough data to calculate the area. Not sufficient. (2) \(AC = BD = \sqrt{2}\) > the diagonals of parallelogram ABCD are equal, which implies that ABCD is a rectangle. Area of a rectangle equals to length*width, so again we don't have enough data to calculate the area. Not sufficient. Notice that you cannot find the area of a rectangle just knowing the length of its diagonal.(1)+(2) ABCD is a rectangle and a rhombus, so it's a square > area=side^2=1^2=1. Sufficient. Answer: C. Hope it's clear.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Manager
Joined: 10 Mar 2014
Posts: 236

Re: What is the area of parallelogram ABCD ? 1. AB = BC = CD = [#permalink]
Show Tags
17 Apr 2014, 06:16
Bunuel wrote: swati007 wrote: I have a doubt in the explanation of this question. The official ans says that all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus but this is the property of square(a parallelogram) as well...?
Yes, both a rhombus and a square have equal sides. From (1) we know that ABCD is a rhombus. A rhombus is a special type of a square, so from (1) ABCD is a rhombus and can be a square. What is the area of parallelogram \(ABCD\)?Notice that we are told that ABCD is a parallelogram. (1) \(AB = BC =CD = DA = 1\) > all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus. Area of a rhombus equals to \(\frac{d_1*d_2}{2}\) (where \(d_1\) and \(d_2\) are the lengths of the diagonals) or \(bh\) (where \(b\) is the length of the base and \(h\) is the altitude), so we don't have enough data to calculate the area. Not sufficient. (2) \(AC = BD = \sqrt{2}\) > the diagonals of parallelogram ABCD are equal, which implies that ABCD is a rectangle. Area of a rectangle equals to length*width, so again we don't have enough data to calculate the area. Not sufficient. Notice that you cannot find the area of a rectangle just knowing the length of its diagonal.(1)+(2) ABCD is a rectangle and a rhombus, so it's a square > area=side^2=1^2=1. Sufficient. Answer: C. Hope it's clear. HI Bunnel, Diagonal of a square is also equals. then if both the diagonals are equal and root 2 then we have side as 1 and we can calculate the area. Please clarify.



Math Expert
Joined: 02 Sep 2009
Posts: 43887

Re: What is the area of parallelogram ABCD ? 1. AB = BC = CD = [#permalink]
Show Tags
17 Apr 2014, 06:27
PathFinder007 wrote: Bunuel wrote: swati007 wrote: I have a doubt in the explanation of this question. The official ans says that all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus but this is the property of square(a parallelogram) as well...?
Yes, both a rhombus and a square have equal sides. From (1) we know that ABCD is a rhombus. A rhombus is a special type of a square, so from (1) ABCD is a rhombus and can be a square. What is the area of parallelogram \(ABCD\)?Notice that we are told that ABCD is a parallelogram. (1) \(AB = BC =CD = DA = 1\) > all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus. Area of a rhombus equals to \(\frac{d_1*d_2}{2}\) (where \(d_1\) and \(d_2\) are the lengths of the diagonals) or \(bh\) (where \(b\) is the length of the base and \(h\) is the altitude), so we don't have enough data to calculate the area. Not sufficient. (2) \(AC = BD = \sqrt{2}\) > the diagonals of parallelogram ABCD are equal, which implies that ABCD is a rectangle. Area of a rectangle equals to length*width, so again we don't have enough data to calculate the area. Not sufficient. Notice that you cannot find the area of a rectangle just knowing the length of its diagonal.(1)+(2) ABCD is a rectangle and a rhombus, so it's a square > area=side^2=1^2=1. Sufficient. Answer: C. Hope it's clear. HI Bunnel, Diagonal of a square is also equals. then if both the diagonals are equal and root 2 then we have side as 1 and we can calculate the area. Please clarify. Please read the red part in my solution. Why should the sides equal to 1? Why cannot they be any numbers satisfying \(x^2+y^2=2\)?
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Math Expert
Joined: 02 Sep 2009
Posts: 43887

Re: What is the area of parallelogram ABCD ? 1. AB = BC = CD = [#permalink]
Show Tags
17 Apr 2014, 06:32
Bunuel wrote: PathFinder007 wrote: Bunuel wrote: Yes, both a rhombus and a square have equal sides. From (1) we know that ABCD is a rhombus. A rhombus is a special type of a square, so from (1) ABCD is a rhombus and can be a square.
What is the area of parallelogram \(ABCD\)?
Notice that we are told that ABCD is a parallelogram.
(1) \(AB = BC =CD = DA = 1\) > all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus. Area of a rhombus equals to \(\frac{d_1*d_2}{2}\) (where \(d_1\) and \(d_2\) are the lengths of the diagonals) or \(bh\) (where \(b\) is the length of the base and \(h\) is the altitude), so we don't have enough data to calculate the area. Not sufficient.
(2) \(AC = BD = \sqrt{2}\) > the diagonals of parallelogram ABCD are equal, which implies that ABCD is a rectangle. Area of a rectangle equals to length*width, so again we don't have enough data to calculate the area. Not sufficient. Notice that you cannot find the area of a rectangle just knowing the length of its diagonal.
(1)+(2) ABCD is a rectangle and a rhombus, so it's a square > area=side^2=1^2=1. Sufficient.
Answer: C.
Hope it's clear.
HI Bunnel, Diagonal of a square is also equals. then if both the diagonals are equal and root 2 then we have side as 1 and we can calculate the area. Please clarify. Please read the red part in my solution. Why should the sides equal to 1? Why cannot they be any numbers satisfying \(x^2+y^2=2\)? For more on this trap check the following questions: thecircularbaseofanabovegroundswimmingpoolliesina167645.htmlfigureabcdisarectanglewithsidesoflengthxcentimete48899.htmlinrighttriangleabcbcisthehypotenuseifbcis13and163591.htmlm227330920.htmlpointsabandclieonacircleofradius1whatisthe84423.htmlifverticesofatrianglehavecoordinates2232and8215920.htmlifpistheperimeterofrectangleqwhatisthevalueofp135832.htmlifthediagonalofrectanglezisdandtheperimeterof104205.htmlwhatistheareaofrectangularregionr105414.htmlwhatistheperimeterofrectangler96381.htmlpythagoreantriples131161.htmlgiventhatabcdisarectangleistheareaoftriangleabe127051.htmlm13q56973220.html#p1176059m2007triangleinsideacircle71559.htmlwhatistheperimeterofrectangler96381.htmlwhatistheareaofrectangularregionr166186.htmlifdistinctpointsabcanddformarighttriangleabc129328.htmlHope this helps.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Manager
Joined: 10 Mar 2014
Posts: 236

Re: What is the area of parallelogram ABCD ? 1. AB = BC = CD = [#permalink]
Show Tags
17 Apr 2014, 07:01
Because diagonal of a square = site root2
now as it is given diagonals are equal and this is also property of a square . so if diagonal is root 2 then my site will be 1. and area of a square would be one.
Thanks



Math Expert
Joined: 02 Sep 2009
Posts: 43887

Re: What is the area of parallelogram ABCD ? 1. AB = BC = CD = [#permalink]
Show Tags
17 Apr 2014, 07:28
PathFinder007 wrote: Because diagonal of a square = site root2
now as it is given diagonals are equal and this is also property of a square . so if diagonal is root 2 then my site will be 1. and area of a square would be one.
Thanks First of all from (2) we know that ABCD is a rectangle, not necessarily a square. Next, the fact that the diagonals equals to \(\sqrt{2}\) does not mean that the sides must be equal to 1. The sides can be: \(\frac{1}{2}\) and \(\frac{\sqrt{7}}{2}\); \(\frac{1}{3}\) and \(\frac{\sqrt{7}}{\sqrt{3}}\); ... Basically the lengths of the sides can be any positive (x, y) satisfying \(x^2+y^2=(\sqrt{2})^2\). Please follow the links in my post above for questions which use the same trap.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Manager
Joined: 10 Mar 2014
Posts: 236

Re: What is the area of parallelogram ABCD ? 1. AB = BC = CD = [#permalink]
Show Tags
17 Apr 2014, 09:41
Bunuel wrote: PathFinder007 wrote: Because diagonal of a square = site root2
now as it is given diagonals are equal and this is also property of a square . so if diagonal is root 2 then my site will be 1. and area of a square would be one.
Thanks First of all from (2) we know that ABCD is a rectangle, not necessarily a square. Next, the fact that the diagonals equals to \(\sqrt{2}\) does not mean that the sides must be equal to 1. The sides can be: \(\frac{1}{2}\) and \(\frac{\sqrt{7}}{2}\); \(\frac{1}{3}\) and \(\frac{\sqrt{7}}{\sqrt{3}}\); ... Basically the lengths of the sides can be any positive (x, y) satisfying \(x^2+y^2=(\sqrt{2})^2\). Please follow the links in my post above for questions which use the same trap. Clear. Thanks for your valuable input.



Manager
Status: Kitchener
Joined: 03 Oct 2013
Posts: 95
Location: Canada
Concentration: Finance, Finance
GPA: 2.9
WE: Education (Education)

What is the area of parallelogram ABCD ? [#permalink]
Show Tags
02 Feb 2015, 15:27
Knesl wrote: What is the area of parallelogram ABCD ?
(1) AB = BC = CD = DA = 1 (2) AC = BD = \(\sqrt{2}\)
(C) 2008 GMAT Club  M1305 Dear Bunuel, can we say  based on statement 2 that the parallelogram could be rhombus? If the answer is not can you tell me why?
_________________
Click +1 Kudos if my post helped



Math Expert
Joined: 02 Sep 2009
Posts: 43887

Re: What is the area of parallelogram ABCD ? [#permalink]
Show Tags
03 Feb 2015, 02:35



Manager
Joined: 27 Jun 2014
Posts: 74
Location: New Zealand
Concentration: Strategy, General Management
GRE 1: 324 Q161 V163 GRE 2: 325 Q159 V166
GPA: 3.6
WE: Editorial and Writing (Computer Software)

Re: What is the area of parallelogram ABCD ? [#permalink]
Show Tags
04 Feb 2015, 16:42
1
This post received KUDOS
Bunuel wrote: swati007 wrote: I have a doubt in the explanation of this question. The official ans says that all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus but this is the property of square(a parallelogram) as well...?
Yes, both a rhombus and a square have equal sides. From (1) we know that ABCD is a rhombus. A rhombus is a special type of a square, so from (1) ABCD is a rhombus and can be a square. What is the area of parallelogram \(ABCD\)?Notice that we are told that ABCD is a parallelogram. (1) \(AB = BC =CD = DA = 1\) > all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus. Area of a rhombus equals to \(\frac{d_1*d_2}{2}\) (where \(d_1\) and \(d_2\) are the lengths of the diagonals) or \(bh\) (where \(b\) is the length of the base and \(h\) is the altitude), so we don't have enough data to calculate the area. Not sufficient. (2) \(AC = BD = \sqrt{2}\) > the diagonals of parallelogram ABCD are equal, which implies that ABCD is a rectangle. Area of a rectangle equals to length*width, so again we don't have enough data to calculate the area. Not sufficient. Notice that you cannot find the area of a rectangle just knowing the length of its diagonal.(1)+(2) ABCD is a rectangle and a rhombus, so it's a square > area=side^2=1^2=1. Sufficient. Answer: C. Hope it's clear. Thanks as always for your valuable and detailed explanations. However, you've mentioned that a 'rhombus is a special type of square', where as a square is a special type of rhombus. Parallelogram>Rectangle/Rhombus>Square.
_________________
"Hardwork is the easiest way to success."  Aviram
One more shot at the GMAT...aiming for a more balanced score.



Math Expert
Joined: 02 Sep 2009
Posts: 43887

Re: What is the area of parallelogram ABCD ? [#permalink]
Show Tags
04 Feb 2015, 16:47
aviram wrote: Bunuel wrote: swati007 wrote: I have a doubt in the explanation of this question. The official ans says that all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus but this is the property of square(a parallelogram) as well...?
Yes, both a rhombus and a square have equal sides. From (1) we know that ABCD is a rhombus. A rhombus is a special type of a square, so from (1) ABCD is a rhombus and can be a square. What is the area of parallelogram \(ABCD\)?Notice that we are told that ABCD is a parallelogram. (1) \(AB = BC =CD = DA = 1\) > all four sides of parallelogram ABCD are equal, which implies that ABCD is a rhombus. Area of a rhombus equals to \(\frac{d_1*d_2}{2}\) (where \(d_1\) and \(d_2\) are the lengths of the diagonals) or \(bh\) (where \(b\) is the length of the base and \(h\) is the altitude), so we don't have enough data to calculate the area. Not sufficient. (2) \(AC = BD = \sqrt{2}\) > the diagonals of parallelogram ABCD are equal, which implies that ABCD is a rectangle. Area of a rectangle equals to length*width, so again we don't have enough data to calculate the area. Not sufficient. Notice that you cannot find the area of a rectangle just knowing the length of its diagonal.(1)+(2) ABCD is a rectangle and a rhombus, so it's a square > area=side^2=1^2=1. Sufficient. Answer: C. Hope it's clear. Thanks as always for your valuable and detailed explanations. However, you've mentioned that a 'rhombus is a special type of square', where as a square is a special type of rhombus. Parallelogram>Rectangle/Rhombus>Square. Typo edited. Thank you.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



NonHuman User
Joined: 09 Sep 2013
Posts: 13791

Re: What is the area of parallelogram ABCD ? [#permalink]
Show Tags
23 Aug 2017, 08:10
Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up  doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Books  GMAT Club Tests  Best Prices on GMAT Courses  GMAT Mobile App  Math Resources  Verbal Resources



Director
Joined: 12 Nov 2016
Posts: 790

Re: What is the area of parallelogram ABCD ? [#permalink]
Show Tags
07 Sep 2017, 19:19
Knesl wrote: What is the area of parallelogram ABCD ?
(1) AB = BC = CD = DA = 1 (2) AC = BD = \(\sqrt{2}\)
(C) 2008 GMAT Club  M1305 Statement 1 Knowing htat the paralleogram has four equal sides is enough to determine that the figure is a rhombus since a rhombus is essentially an equilateral paralleogram. But we do not know the diagonal length of this rhombus and we cannot calculate the lengths of the diagonals with just the length of the sides. Insuff Statement 2 Knowing that the parallelogram has two equal diagonals implies that the parallelogram is a rectangle... But what kind of rectangle? A square? If it we knew that that the parallelogram was a square then we could calculate the area of it by simply squaring the diagonal lengths and dividing by 2. Logically, a square IS a rhombus because the diagonals of a square can be squared and then divided by 2 in order to find the area. C




Re: What is the area of parallelogram ABCD ?
[#permalink]
07 Sep 2017, 19:19






