It is currently 17 Feb 2018, 13:39

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

Events & Promotions in June
Open Detailed Calendar

In the figure above, if the perimeter of quadrilateral ABCD is 24, wha

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

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43785
In the figure above, if the perimeter of quadrilateral ABCD is 24, wha [#permalink]

Show Tags

New post 04 Oct 2017, 10:13
Expert's post
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

82% (01:59) correct 18% (02:02) wrong based on 116 sessions

HideShow timer Statistics

Image
In the figure above, if the perimeter of quadrilateral ABCD is 24, what is the area of ∆ ECD?

(A) 12
(B) 15
(C) 20
(D) 24
(E) 30

[Reveal] Spoiler:
Attachment:
2017-10-04_1123_002.png
2017-10-04_1123_002.png [ 8.04 KiB | Viewed 1223 times ]
[Reveal] Spoiler: OA

_________________

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

1 KUDOS received
PS Forum Moderator
avatar
P
Joined: 25 Feb 2013
Posts: 919
Location: India
GPA: 3.82
GMAT ToolKit User Premium Member Reviews Badge CAT Tests
Re: In the figure above, if the perimeter of quadrilateral ABCD is 24, wha [#permalink]

Show Tags

New post 04 Oct 2017, 10:29
1
This post received
KUDOS
Bunuel wrote:
Image
In the figure above, if the perimeter of quadrilateral ABCD is 24, what is the area of ∆ ECD?

(A) 12
(B) 15
(C) 20
(D) 24
(E) 30

[Reveal] Spoiler:
Attachment:
2017-10-04_1123_002.png


As \(BC || AD\), angle \(BCE=CED=x°\). Hence triangle \(ECD\) is isosceles with \(CE=CD=5\)

Given perimeter of \(ABCD=24\), so \(AD=24-(3+6+5)=10\)

\(ED=AD-AE=10-2=8\)

Height of triangle \(ECD = AB = 3\) and Base \(ED=8\)

So area \(= \frac{1}{2}*3*8=12\)

Option A
1 KUDOS received
Senior Manager
Senior Manager
avatar
G
Joined: 24 Apr 2016
Posts: 333
Re: In the figure above, if the perimeter of quadrilateral ABCD is 24, wha [#permalink]

Show Tags

New post 04 Oct 2017, 10:39
1
This post received
KUDOS
As BC is parallel to AD, Angle BCE = Angle CED = X

Since Angles BCE & CED are equal, Triangle ECD is isosceles, therefore CD = EC = 5

Perimeter of ABCD = AB + BC + CD + AE + ED = 3 + 6 + 5 + 2 + ED = 24 ==> ED = 8

Height of Triangle ECD is 3

Area of Triangle ECD = \(\frac{1}{2}\) * 8 * 3 = 12

Answer is A
Attachments

Untitled.png
Untitled.png [ 14.43 KiB | Viewed 1063 times ]

Intern
Intern
avatar
B
Joined: 01 May 2017
Posts: 4
Re: In the figure above, if the perimeter of quadrilateral ABCD is 24, wha [#permalink]

Show Tags

New post 03 Nov 2017, 10:58
Bunuel can you explain how 24?
PS Forum Moderator
avatar
P
Joined: 25 Feb 2013
Posts: 919
Location: India
GPA: 3.82
GMAT ToolKit User Premium Member Reviews Badge CAT Tests
Re: In the figure above, if the perimeter of quadrilateral ABCD is 24, wha [#permalink]

Show Tags

New post 03 Nov 2017, 18:41
bara25 wrote:
Bunuel can you explain how 24?


Hi Bunuel

I agree with bara25. Kindly provide the OA or can you highlight the errors in my approach. IMO answer should be 12
Intern
Intern
User avatar
B
Joined: 29 May 2012
Posts: 39
Premium Member
Re: In the figure above, if the perimeter of quadrilateral ABCD is 24, wha [#permalink]

Show Tags

New post 03 Nov 2017, 19:28
I can't work out 24 either. My answer is A like many of you. Awaiting for the OA.
Expert Post
1 KUDOS received
Math Expert
User avatar
D
Joined: 02 Aug 2009
Posts: 5647
Re: In the figure above, if the perimeter of quadrilateral ABCD is 24, wha [#permalink]

Show Tags

New post 03 Nov 2017, 19:42
1
This post received
KUDOS
Expert's post
Bunuel wrote:
Image
In the figure above, if the perimeter of quadrilateral ABCD is 24, what is the area of ∆ ECD?

(A) 12
(B) 15
(C) 20
(D) 24
(E) 30

[Reveal] Spoiler:
Attachment:
2017-10-04_1123_002.png



hi Bunuel
there seems to be some typo..
Either the answer is for AREA of trapezium ABCD.. then it is 24
or typo in OA, as ans should be 12
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html


BANGALORE/-

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43785
Re: In the figure above, if the perimeter of quadrilateral ABCD is 24, wha [#permalink]

Show Tags

New post 03 Nov 2017, 22:35
chetan2u wrote:
Bunuel wrote:
Image
In the figure above, if the perimeter of quadrilateral ABCD is 24, what is the area of ∆ ECD?

(A) 12
(B) 15
(C) 20
(D) 24
(E) 30

[Reveal] Spoiler:
Attachment:
2017-10-04_1123_002.png



hi Bunuel
there seems to be some typo..
Either the answer is for AREA of trapezium ABCD.. then it is 24
or typo in OA, as ans should be 12


The OA is A. Edited. Sorry for that.
_________________

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

Manager
Manager
avatar
B
Joined: 24 Jun 2017
Posts: 121
Re: In the figure above, if the perimeter of quadrilateral ABCD is 24, wha [#permalink]

Show Tags

New post 04 Nov 2017, 07:45
darn it:)) I killed myself yesterday, solved for A in 1 min, the OA was 24, and spent like 1h trying to figure out how the hell on earth that can be 24 :)) solved like in 3 different way, 12 again :)
Intern
Intern
avatar
B
Joined: 08 Aug 2017
Posts: 24
Re: In the figure above, if the perimeter of quadrilateral ABCD is 24, wha [#permalink]

Show Tags

New post 17 Nov 2017, 02:36
Question needs more information because given information doesn't means neither that AD II BC nor AB is perpendicular to AD.
Provided information is not sufficient to reach at answer.
Expert Post
Math Expert
User avatar
D
Joined: 02 Aug 2009
Posts: 5647
Re: In the figure above, if the perimeter of quadrilateral ABCD is 24, wha [#permalink]

Show Tags

New post 17 Nov 2017, 03:31
gvij2017 wrote:
Question needs more information because given information doesn't means neither that AD II BC nor AB is perpendicular to AD.
Provided information is not sufficient to reach at answer.



Hi..
It is clearly given that AB is perpendicular to AD by showing sign of L at the angle. A squarish box at the angle tells us that angle is 90..
Also if two sides on the base are 90°, the two sides will be perpendicular since both are at same angle.

Seems you are misunderstanding something
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html


BANGALORE/-

Re: In the figure above, if the perimeter of quadrilateral ABCD is 24, wha   [#permalink] 17 Nov 2017, 03:31
Display posts from previous: Sort by

In the figure above, if the perimeter of quadrilateral ABCD is 24, wha

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


GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.