GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 16 Dec 2018, 18:56

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • 10 Keys to nail DS and CR questions

     December 17, 2018

     December 17, 2018

     06:00 PM PST

     07:00 PM PST

    Join our live webinar and learn how to approach Data Sufficiency and Critical Reasoning problems, how to identify the best way to solve each question and what most people do wrong.
  • FREE Quant Workshop by e-GMAT!

     December 16, 2018

     December 16, 2018

     07:00 AM PST

     09:00 AM PST

    Get personalized insights on how to achieve your Target Quant Score.

Is quadrilateral ABCD a square?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Retired Moderator
avatar
Joined: 29 Apr 2015
Posts: 843
Location: Switzerland
Concentration: Economics, Finance
Schools: LBS MIF '19
WE: Asset Management (Investment Banking)
GMAT ToolKit User Premium Member
Is quadrilateral ABCD a square?  [#permalink]

Show Tags

New post 28 Sep 2015, 03:05
1
11
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

43% (01:17) correct 57% (01:14) wrong based on 242 sessions

HideShow timer Statistics

Is quadrilateral ABCD a square?

(1) ABCD is a rectangle whose diagonals intersect at right angles.
(2) AC, a diagonal of ABCD, is also the hypotenuse of isosceles right triangles ABC and ADC.

_________________

Saving was yesterday, heat up the gmatclub.forum's sentiment by spending KUDOS!

PS Please send me PM if I do not respond to your question within 24 hours.

Intern
Intern
avatar
Joined: 02 Feb 2014
Posts: 4
Re: Is quadrilateral ABCD a square?  [#permalink]

Show Tags

New post 28 Sep 2015, 04:41
Answer should be A

I also had the same issue. I went through all the properties of different quadrilaterals.

1. ABCD is a rectangle and if diagnals intersect at 90 degree, square is the only option. Suff.

2. In the second case, it can be either square or a kite as per the given properties Insuff.
Retired Moderator
avatar
Joined: 29 Apr 2015
Posts: 843
Location: Switzerland
Concentration: Economics, Finance
Schools: LBS MIF '19
WE: Asset Management (Investment Banking)
GMAT ToolKit User Premium Member
Re: Is quadrilateral ABCD a square?  [#permalink]

Show Tags

New post 28 Sep 2015, 04:52
Answer is D, the second cannot be a kite
_________________

Saving was yesterday, heat up the gmatclub.forum's sentiment by spending KUDOS!

PS Please send me PM if I do not respond to your question within 24 hours.

CEO
CEO
avatar
S
Joined: 20 Mar 2014
Posts: 2633
Concentration: Finance, Strategy
Schools: Kellogg '18 (M)
GMAT 1: 750 Q49 V44
GPA: 3.7
WE: Engineering (Aerospace and Defense)
GMAT ToolKit User Premium Member Reviews Badge
Re: Is quadrilateral ABCD a square?  [#permalink]

Show Tags

New post Updated on: 28 Sep 2015, 10:32
1
reto wrote:
Is quadrilateral ABCD a square?

(1) ABCD is a rectangle whose diagonals intersect at right angles.
(2) AC, a diagonal of ABCD, is also the hypotenuse of isosceles right triangles ABC and ADC.

I am always struggling with such questions. Any sources to prepare for those?


reto, look at the attached picture of quadrilateral family in GMAT. It is taken from https://en.wikipedia.org/wiki/Rhombus

Statement 2, is sufficient to answer as it can only be a square. Kite would have been possible had the statement mentioned that the triangles are isosceles but not necessarily right angled.

Statement 1 eliminates rhombus as it is not a rectangle.

Thus D is the correct answer.
Attachments

Symmetries_of_square.svg.png
Symmetries_of_square.svg.png [ 30.7 KiB | Viewed 2461 times ]


Originally posted by ENGRTOMBA2018 on 28 Sep 2015, 05:04.
Last edited by ENGRTOMBA2018 on 28 Sep 2015, 10:32, edited 1 time in total.
Updated the picture
CEO
CEO
avatar
S
Joined: 20 Mar 2014
Posts: 2633
Concentration: Finance, Strategy
Schools: Kellogg '18 (M)
GMAT 1: 750 Q49 V44
GPA: 3.7
WE: Engineering (Aerospace and Defense)
GMAT ToolKit User Premium Member Reviews Badge
Re: Is quadrilateral ABCD a square?  [#permalink]

Show Tags

New post 28 Sep 2015, 05:07
apoorva2890 wrote:
Answer should be A

I also had the same issue. I went through all the properties of different quadrilaterals.

1. ABCD is a rectangle and if diagnals intersect at 90 degree, square is the only option. Suff.

2. In the second case, it can be either square or a kite as per the given properties Insuff.


It can not be a kite as the resulting triangle must be RIGHT ANGLED ISOSCELES triangle. Kite does not provide that. Thus, square is the only option.
Retired Moderator
avatar
Joined: 29 Apr 2015
Posts: 843
Location: Switzerland
Concentration: Economics, Finance
Schools: LBS MIF '19
WE: Asset Management (Investment Banking)
GMAT ToolKit User Premium Member
Re: Is quadrilateral ABCD a square?  [#permalink]

Show Tags

New post 28 Sep 2015, 09:59
Engr2012 wrote:
reto wrote:
Is quadrilateral ABCD a square?

(1) ABCD is a rectangle whose diagonals intersect at right angles.
(2) AC, a diagonal of ABCD, is also the hypotenuse of isosceles right triangles ABC and ADC.

I am always struggling with such questions. Any sources to prepare for those?


reto, look at the attached picture of quadrilateral family in GMAT.

Statement 2, is sufficient to answer as it can only be a square. Kite would have been possible had the statement mentioned that the triangles are isosceles but not necessarily right angled.

Statement 1 eliminates rhombus as it is not a rectangle.

Thus D is the correct answer.


Thanks - I also found this overview here: quadrilateral-properties-136155.html#p1106572
_________________

Saving was yesterday, heat up the gmatclub.forum's sentiment by spending KUDOS!

PS Please send me PM if I do not respond to your question within 24 hours.

CEO
CEO
avatar
S
Joined: 20 Mar 2014
Posts: 2633
Concentration: Finance, Strategy
Schools: Kellogg '18 (M)
GMAT 1: 750 Q49 V44
GPA: 3.7
WE: Engineering (Aerospace and Defense)
GMAT ToolKit User Premium Member Reviews Badge
Re: Is quadrilateral ABCD a square?  [#permalink]

Show Tags

New post 28 Sep 2015, 10:07
1
reto wrote:
Engr2012 wrote:
reto wrote:
Is quadrilateral ABCD a square?

(1) ABCD is a rectangle whose diagonals intersect at right angles.
(2) AC, a diagonal of ABCD, is also the hypotenuse of isosceles right triangles ABC and ADC.

I am always struggling with such questions. Any sources to prepare for those?


reto, look at the attached picture of quadrilateral family in GMAT.

Statement 2, is sufficient to answer as it can only be a square. Kite would have been possible had the statement mentioned that the triangles are isosceles but not necessarily right angled.

Statement 1 eliminates rhombus as it is not a rectangle.

Thus D is the correct answer.


Thanks - I also found this overview here: quadrilateral-properties-136155.html#p1106572


Instead of just rote memorizing these properties make sure to draw them out so that you remember how to apply these properties as well.
Intern
Intern
avatar
B
Joined: 24 Oct 2014
Posts: 16
Location: Spain
Schools: LBS '21 (II)
Re: Is quadrilateral ABCD a square?  [#permalink]

Show Tags

New post 08 Jan 2018, 11:01
I don't understand why (1) is Suff.

Don't the diagonals of rhombus intersect at 90º?
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51229
Re: Is quadrilateral ABCD a square?  [#permalink]

Show Tags

New post 08 Jan 2018, 19:50
Fernandocma wrote:
I don't understand why (1) is Suff.

Don't the diagonals of rhombus intersect at 90º?


(1) says that ABCD is a rectangle. Rectangular rhombus is a square.

Check Properties of Polygons Questions for similar problems.

23. Geometry




24. Coordinate Geometry




25. Triangles




26. Polygons




27. Circles




28. Rectangular Solids and Cylinders




29. Graphs and Illustrations




For other subjects:
ALL YOU NEED FOR QUANT ! ! !
Ultimate GMAT Quantitative Megathread

Hope it 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?
Extra-hard Quant Tests with Brilliant Analytics

GMAT Club Bot
Re: Is quadrilateral ABCD a square? &nbs [#permalink] 08 Jan 2018, 19:50
Display posts from previous: Sort by

Is quadrilateral ABCD a square?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.