Two squares overlapped

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 328
Joined: Thu Aug 07, 2008 5:25 pm
Location: Philadelphia
Thanked: 4 times
GMAT Score:550

Two squares overlapped

by Abdulla » Thu Jun 25, 2009 3:54 pm
What is the area of the region in which squares ABCD and EFGH overlap?

(1) EF bisects BC.

(2) The distance from point C to point E is and the distance from point C to point F is .

The diagram is attached.

OA is B

Why the first statement is wrong?
Attachments
Picture 3.png
Overlaped squares.pages.zip
(51.45 KiB) Downloaded 60 times
Last edited by Abdulla on Fri Jun 26, 2009 11:33 am, edited 1 time in total.
Abdulla

Junior | Next Rank: 30 Posts
Posts: 29
Joined: Thu Apr 30, 2009 1:32 pm
Thanked: 2 times

by shanmugam.d » Fri Jun 26, 2009 4:22 am
cant open your attachment, can u upload just the jpeg image or word doc?

Master | Next Rank: 500 Posts
Posts: 328
Joined: Thu Aug 07, 2008 5:25 pm
Location: Philadelphia
Thanked: 4 times
GMAT Score:550

by Abdulla » Fri Jun 26, 2009 11:34 am
Thanks shanmugam.d

Check it now
Abdulla

User avatar
Master | Next Rank: 500 Posts
Posts: 472
Joined: Sun Mar 29, 2009 6:54 pm
Thanked: 56 times

by ssmiles08 » Fri Jun 26, 2009 1:10 pm
IMO B.

statement 1 is not enough b/c you don't know the actual values of the sides of each squares. Both square could have been equal in length and the result of the overlapping figure would be a square. But if one square was twice the length of the second square, the overlapping area would be that of a rectangle.

2) would produce a 45-45-90 triangle which would make EF = 4.

when you make EF = 4, FG = 4, EG = 4sqrt(2)

you know EC = 2sqrt(2) which is exactly 1/2 of EG.

The overlapping region is a square with a side length of 2, so area is 4.

Junior | Next Rank: 30 Posts
Posts: 29
Joined: Thu Apr 30, 2009 1:32 pm
Thanked: 2 times

by shanmugam.d » Fri Jun 26, 2009 1:29 pm
(1) says that EF bisects BC

- means BC is divided exactly into two halves.
So we can get one side of the small square/ rectangle, but we dont have clue about the other side of the small square/ rectangle

- Not sufficient

(2) says the distance CE = CF =2√2
We know the diagonal of sqaure is xV2, we have x =4, hence diagonal is 4√2.
Thus we can conclude that E is mid point of diagonal AC and C mid point of diagonal HF, and the overlapped portions is a square of side = 2
- Sufficient
answer = (B)

Master | Next Rank: 500 Posts
Posts: 328
Joined: Thu Aug 07, 2008 5:25 pm
Location: Philadelphia
Thanked: 4 times
GMAT Score:550

by Abdulla » Fri Jun 26, 2009 1:38 pm
Guys, I am confused with the wording in the question where it says "What is the area of the region in which squares ABCD and EFGH overlap? " but you guys are saying that it could be square or rectangular ?

Can someone explain ??[/u]
Abdulla

User avatar
Master | Next Rank: 500 Posts
Posts: 472
Joined: Sun Mar 29, 2009 6:54 pm
Thanked: 56 times

by ssmiles08 » Fri Jun 26, 2009 1:55 pm
Abdulla wrote:Guys, I am confused with the wording in the question where it says "What is the area of the region in which squares ABCD and EFGH overlap? " but you guys are saying that it could be square or rectangular ?

Can someone explain ??[/u]
OOH i totally missed the part where it gives the side length of 4 for both squares. So they ARE identical to each other. If EF bisects BC, then I would presume that EH bisects DC as well, so it would be sufficient??...

IMO D.

maybe we are missing something? hopefully someone can point it out...Do you have the OE?

Master | Next Rank: 500 Posts
Posts: 328
Joined: Thu Aug 07, 2008 5:25 pm
Location: Philadelphia
Thanked: 4 times
GMAT Score:550

by Abdulla » Fri Jun 26, 2009 5:49 pm
here is the explanations can you explain it :D
Attachments
Picture 6.png
Abdulla

Legendary Member
Posts: 1161
Joined: Mon May 12, 2008 2:52 am
Location: Sydney
Thanked: 23 times
Followed by:1 members

by mehravikas » Fri Jun 26, 2009 8:51 pm
From statement 1, we dont know whether EH bisects DC
Abdulla wrote:here is the explanations can you explain it :D

Junior | Next Rank: 30 Posts
Posts: 29
Joined: Thu Apr 30, 2009 1:32 pm
Thanked: 2 times

by shanmugam.d » Sun Jun 28, 2009 11:11 pm
Hi ABdulla, hope the attachment explains your doubt
Attachments
Sans titre.JPG

Legendary Member
Posts: 1169
Joined: Sun Jul 06, 2008 2:34 am
Thanked: 25 times
Followed by:1 members

by aj5105 » Sun Jun 28, 2009 11:58 pm
great effort Shanmugam.

Master | Next Rank: 500 Posts
Posts: 328
Joined: Thu Aug 07, 2008 5:25 pm
Location: Philadelphia
Thanked: 4 times
GMAT Score:550

by Abdulla » Mon Jun 29, 2009 1:03 pm
shanmugam.d wrote:Hi ABdulla, hope the attachment explains your doubt
Thanks buddy. It was a great explanation.
Abdulla