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

It is currently 18 Oct 2019, 01:48

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

In the figure above, square CDEF has area 4.

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

Hide Tags

Find Similar Topics 
Retired Moderator
avatar
V
Joined: 22 Jun 2014
Posts: 1093
Location: India
Concentration: General Management, Technology
GMAT 1: 540 Q45 V20
GPA: 2.49
WE: Information Technology (Computer Software)
GMAT ToolKit User
In the figure above, square CDEF has area 4.  [#permalink]

Show Tags

New post 03 Dec 2018, 07:24
2
5
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

81% (01:31) correct 19% (02:13) wrong based on 156 sessions

HideShow timer Statistics

Image

In the figure above, square CDEF has area 4. What is the area of △ ABF?

(A) 2\(\sqrt{2}\)
(B) 2\(\sqrt{3}\)
(C) 4
(D) 3\(\sqrt{3}\)
(E) 6

Project PS Butler : Question #56


Subscribe to get Daily Email - Click Here | Subscribe via RSS - RSS

Attachment:
ABF.JPG
ABF.JPG [ 19.41 KiB | Viewed 1796 times ]

_________________
Manager
Manager
User avatar
G
Joined: 07 Aug 2018
Posts: 108
Location: United States (MA)
GMAT 1: 560 Q39 V28
GMAT 2: 670 Q48 V34
Re: In the figure above, square CDEF has area 4.  [#permalink]

Show Tags

New post 03 Dec 2018, 10:48
2
IMO E

Triangle \(CFB\) is a 30-60-90 triangle, therefore is side \(FB=2*\sqrt{3}\)...

Triangle \(ABF\) is a 45-45-90 triangle (isosceles right triangle), therefore is side \(BF=AB\) and the hypotenuse is equal to \(2*\sqrt{3}*\sqrt{2}\)

Area of \(ABF=\) \(\frac{1}{2}*2*\sqrt{3}*2*\sqrt{3}=\)\(6\)
Attachments

Screen Shot 2018-12-03 at 18.36.52.png
Screen Shot 2018-12-03 at 18.36.52.png [ 134.78 KiB | Viewed 1626 times ]


_________________
GMAT Club Legend
GMAT Club Legend
User avatar
V
Joined: 12 Sep 2015
Posts: 4007
Location: Canada
Re: In the figure above, square CDEF has area 4.  [#permalink]

Show Tags

New post 17 Jan 2019, 12:33
Top Contributor
HKD1710 wrote:
Image

In the figure above, square CDEF has area 4. What is the area of △ ABF?

(A) 2\(\sqrt{2}\)
(B) 2\(\sqrt{3}\)
(C) 4
(D) 3\(\sqrt{3}\)
(E) 6

Project PS Butler : Question #56


Subscribe to get Daily Email - Click Here | Subscribe via RSS - RSS

Attachment:
ABF.JPG


If the area of the square is 4, then each side has length 2
Image

At this point, we have a special 30-60-90 right triangle. When we compare this blue triangle to the BASE 30-60-90 right triangle . . .
Image
. . . we see that the blue triangle TWICE the size of the BASE 30-60-90 right triangle

So, These are the measurements of the blue triangle
Image


Finally, we have special 45-45-90 right triangle.
Image

This triangle is also an ISOSCELES triangle, so the other side ALSO has length 2√3
Image

What is the area of △ABF?
area of a triangle = (base)(height)/2

So, area of △ABF = (2√3)(2√3)/2
= (4√9)/2
= (4)(3)/2
= 12/2
= 6

Answer: E

Cheers,
Brent
_________________
Test confidently with gmatprepnow.com
Image
Director
Director
avatar
G
Joined: 09 Mar 2018
Posts: 994
Location: India
Re: In the figure above, square CDEF has area 4.  [#permalink]

Show Tags

New post 10 Feb 2019, 21:20
HKD1710 wrote:

In the figure above, square CDEF has area 4. What is the area of △ ABF?

(A) 2\(\sqrt{2}\)
(B) 2\(\sqrt{3}\)
(C) 4
(D) 3\(\sqrt{3}\)
(E) 6



First let us calculate the side CF through the given area of square
side becomes 2

After this triangle CFB will be a 30 60 90 triangle

From here we can get the corresponding side FB as 2 \(\sqrt{3}\)

Now since △ ABF, is an isosceles triangle, the height and base will be equal

1/2 * 2 \(\sqrt{3}\) * 2 \(\sqrt{3}\)

6

E
_________________
If you notice any discrepancy in my reasoning, please let me know. Lets improve together.

Quote which i can relate to.
Many of life's failures happen with people who do not realize how close they were to success when they gave up.
GMAT Club Bot
Re: In the figure above, square CDEF has area 4.   [#permalink] 10 Feb 2019, 21:20
Display posts from previous: Sort by

In the figure above, square CDEF has area 4.

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





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