perimeter of triangle GT Perimeter of Square S

Expert replies

M811: Junior | Next Rank: 30 Posts; Posts: 18; Joined: Sun Nov 22, 2009 4:59 am; Thanked: 1 times

by M811 » Wed May 12, 2010 6:04 pm

Is the perimeter of triangle T greater than the perimeter of square S ?
(1) T is an isoceles right triangle.
(2) The length of the longest side of T is equal to the length of a diagonal of S.

[spoiler]Ans : C[/spoiler]

Last edited by M811 on Wed May 12, 2010 6:49 pm, edited 1 time in total.

Like this post

Source: Beat The GMAT — Data Sufficiency | Wed May 12, 2010 6:04 pm

liferocks: Legendary Member; Posts: 576; Joined: Sat Mar 13, 2010 8:31 pmFollowed by: 1 member; Thanked: 97 times

by liferocks » Wed May 12, 2010 6:27 pm

Clearly 1 alone is not sufficient as it does not provode any relation between the sides of the triangle and square.

From 2
if the length of the sides of the square is a..diagonal aV2

longest side of triangle is aV2...perimeter will be maximum when the triangle is equilateral with side aV2

in that case perimeter is 3aV2 or approximately 4.2a>perimeter of square(4a)
if the triangle is an isoceles right triangle perimeter =aV2(V2+1)<4a...insufficient

together
perimeter of T=aV2(V2+1)
perimeter of S=4a
hence perimeter of triangle T is less than the perimeter of square S..sufficient

Ans option C

please use spoiler for OA.

"If you don't know where you are going, any road will get you there."
Lewis Carroll

Like this post

arora007: Community Manager; Posts: 1048; Joined: Mon Aug 17, 2009 3:26 amFollowed by: 27 members; Location: India; Thanked: 51 times; GMAT Score:670

by arora007 » Wed Aug 11, 2010 9:19 pm

I fail to agree with the OA, I think its E.

we are clear thats its a C or E case, wont go into its details...

now, the perimeter of square is 2root2 t = 2.82t

THE TWIST, the question is written in such a manner that its not clear that the longest sides is the congruent part or not the congrument part....

If I consider a case of congruent part the the 2 sides are t+t = 2t
and the third side is something less than t

so, the triangle perimeter is less than 3t but greater than 2t in any circumstance.

thus it can be greater than 2.82t or less than 2.82t , thus I conclude E.

Can Experts please confirm ??

https://www.skiponemeal.org/
https://twitter.com/skiponemeal
Few things are impossible to diligence & skill.Great works are performed not by strength,but by perseverance

pm me if you find junk/spam/abusive language, Lets keep our community clean!!

Like this post

kvcpk: Legendary Member; Posts: 1893; Joined: Sun May 30, 2010 11:48 pmFollowed by: 7 members; Thanked: 215 times

by kvcpk » Wed Aug 11, 2010 9:55 pm

arora007 wrote:I fail to agree with the OA, I think its E.

we are clear thats its a C or E case, wont go into its details...

now, the perimeter of square is 2root2 t = 2.82t

THE TWIST, the question is written in such a manner that its not clear that the longest sides is the congruent part or not the congrument part....

If I consider a case of congruent part the the 2 sides are t+t = 2t
and the third side is something less than t

so, the triangle perimeter is less than 3t but greater than 2t in any circumstance.

thus it can be greater than 2.82t or less than 2.82t , thus I conclude E.

Can Experts please confirm ??

Hi Arora,

I think you have missed that T is Isoceles Right Triangle.

"Once you start working on something,
don't be afraid of failure and don't abandon it.
People who work sincerely are the happiest."
Chanakya quotes (Indian politician, strategist and writer, 350 BC-275BC)

Like this post

arora007: Community Manager; Posts: 1048; Joined: Mon Aug 17, 2009 3:26 amFollowed by: 27 members; Location: India; Thanked: 51 times; GMAT Score:670

by arora007 » Wed Aug 11, 2010 10:26 pm

kvcpk wrote:
arora007 wrote:I fail to agree with the OA, I think its E.

we are clear thats its a C or E case, wont go into its details...

now, the perimeter of square is 2root2 t = 2.82t

THE TWIST, the question is written in such a manner that its not clear that the longest sides is the congruent part or not the congrument part....

If I consider a case of congruent part the the 2 sides are t+t = 2t
and the third side is something less than t

so, the triangle perimeter is less than 3t but greater than 2t in any circumstance.

thus it can be greater than 2.82t or less than 2.82t , thus I conclude E.

Can Experts please confirm ??
Hi Arora,

I think you have missed that T is Isoceles Right Triangle.

u are right!

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review