Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

It is currently 18 Jul 2019, 22:59

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

If the length of side AB is 17, is triangle ABC a right tria

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

Hide Tags

Find Similar Topics 
Senior Manager
Senior Manager
avatar
Status: Finally Done. Admitted in Kellogg for 2015 intake
Joined: 25 Jun 2011
Posts: 462
Location: United Kingdom
Concentration: International Business, Strategy
GMAT 1: 730 Q49 V45
GPA: 2.9
WE: Information Technology (Consulting)
If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 05 Feb 2012, 04:13
2
6
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

70% (01:15) correct 30% (01:36) wrong based on 298 sessions

HideShow timer Statistics


If the length of side AB is 17, is triangle ABC a right triangle?

(1) The length of side BC is 144.
(2) The length of side AC is 145.

_________________
Best Regards,
E.

MGMAT 1 --> 530
MGMAT 2--> 640
MGMAT 3 ---> 610
GMAT ==> 730
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 56260
Re: Is ABC a right angle triangle?  [#permalink]

Show Tags

New post 05 Feb 2012, 04:26
2
enigma123 wrote:
If the length of side AB is 17, is triangle ABC a right triangle?
(1) The length of side BC is 144.
(2) The length of side AC is 145.

I have got the answer C and its the correct answer. But I arrived at answer by doing the actual calculation. Is there any shortcut?


If the length of side AB is 17, is triangle ABC a right triangle?

(1) The length of side BC is 144 --> there are infinitely many triangles possible with the sides of 17 and 144, two of them will be right triangles (17^2+144^2=x^2, where x is a hypotenuse and 17^2+y^2=144^2, where y is an another leg) and others will not. Not sufficient.

(2) The length of side AC is 145. Not sufficient for the same reason.

(1)+(2) We know all the sides hence, even without actual calculation, we can find out whether the triangle is right or not. Sufficient. (As a matter of fact it is a right triangle: 17^2+144^2=145^2)

Answer: C.
_________________
Manager
Manager
avatar
B
Joined: 31 Jan 2012
Posts: 70
Re: If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 05 Feb 2012, 11:20
Bunuel or anyone else can I ask a question. So if a triangle fits into the Pa Theorem then it has to be a right angle or could it fit the theorem n not be a right angle. Thanks
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 56260
Re: If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 05 Feb 2012, 11:29
Manager
Manager
avatar
Joined: 16 May 2011
Posts: 56
tr  [#permalink]

Show Tags

New post 10 Feb 2012, 08:18
(1) INSUFFICIENT: With only two sides of the triangle, it is impossible to determine whether a2 + b2 = c2.

(2) INSUFFICIENT: With only two sides of the triangle, it is impossible to determine whether a2 + b2 = c2.

(1) AND (2) SUFFICIENT: With all three side lengths, we can determine if a2 + b2 = c2. It turns out that 172 + 1442 = 1452, so this is a right triangle. However, even if it were not a right triangle, this formula would still be sufficient, so it is unnecessary to finish the calculation.
Senior Manager
Senior Manager
avatar
Status: Gonna rock this time!!!
Joined: 22 Jul 2012
Posts: 433
Location: India
GMAT 1: 640 Q43 V34
GMAT 2: 630 Q47 V29
WE: Information Technology (Computer Software)
Re: If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 20 Sep 2012, 02:34
Hi Experts,
Do we really see such calculation intensive Questions on GMAT? :shock:
Regards,
Sachin
_________________
hope is a good thing, maybe the best of things. And no good thing ever dies.

Who says you need a 700 ?Check this out : http://gmatclub.com/forum/who-says-you-need-a-149706.html#p1201595

My GMAT Journey : http://gmatclub.com/forum/end-of-my-gmat-journey-149328.html#p1197992
Director
Director
User avatar
Status: Done with formalities.. and back..
Joined: 15 Sep 2012
Posts: 583
Location: India
Concentration: Strategy, General Management
Schools: Olin - Wash U - Class of 2015
WE: Information Technology (Computer Software)
GMAT ToolKit User Reviews Badge
Re: If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 20 Sep 2012, 03:22
sachindia wrote:
Hi Experts,
Do we really see such calculation intensive Questions on GMAT? :shock:
Regards,
Sachin

Actually there is no intensive calculation involved. The only calculation required here is to check - when combining statement 1 and 2, a triangle can be formed or not, that is sum of 2 lengths is greater than third or not.
Once it is known that a triangle can be formed and you have lenght of each side, you have sufficient details to answer if it is a right angle or not. Data sufficiency question wants to know only that. you dont need to apply theorem to calculate it.
_________________
Lets Kudos!!! ;-)
Black Friday Debrief
Senior Manager
Senior Manager
avatar
Status: Gonna rock this time!!!
Joined: 22 Jul 2012
Posts: 433
Location: India
GMAT 1: 640 Q43 V34
GMAT 2: 630 Q47 V29
WE: Information Technology (Computer Software)
Re: If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 20 Sep 2012, 03:27
I beg to differ..
Its already stated that it is a triangle, Our job is to check if its a right angled triangle..and to check that we need to apply the theorem of the great pythagorus and this application of theorem in my opinion is calculation intensive.

Regards,
Sachin
_________________
hope is a good thing, maybe the best of things. And no good thing ever dies.

Who says you need a 700 ?Check this out : http://gmatclub.com/forum/who-says-you-need-a-149706.html#p1201595

My GMAT Journey : http://gmatclub.com/forum/end-of-my-gmat-journey-149328.html#p1197992
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 56260
Re: If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 20 Sep 2012, 03:33
sachindia wrote:
I beg to differ..
Its already stated that it is a triangle, Our job is to check if its a right angled triangle..and to check that we need to apply the theorem of the great pythagorus and this application of theorem in my opinion is calculation intensive.

Regards,
Sachin


Please check the following post to see that no calculations are needed to solve the question: if-the-length-of-side-ab-is-17-is-triangle-abc-a-right-tria-127069.html#p1039631
_________________
Senior Manager
Senior Manager
avatar
Status: Gonna rock this time!!!
Joined: 22 Jul 2012
Posts: 433
Location: India
GMAT 1: 640 Q43 V34
GMAT 2: 630 Q47 V29
WE: Information Technology (Computer Software)
Re: If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 20 Sep 2012, 03:40
Oh yeah.. :lol:

Its only a DS Question not a PS. :P

Thanks Bunuel..
_________________
hope is a good thing, maybe the best of things. And no good thing ever dies.

Who says you need a 700 ?Check this out : http://gmatclub.com/forum/who-says-you-need-a-149706.html#p1201595

My GMAT Journey : http://gmatclub.com/forum/end-of-my-gmat-journey-149328.html#p1197992
Manager
Manager
avatar
Joined: 18 May 2010
Posts: 66
Re: If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 06 Oct 2012, 06:12
For such large calculations, how do you find out that it's a right triangle? Thanks.
Intern
Intern
avatar
Joined: 28 Aug 2012
Posts: 41
Location: Austria
GMAT 1: 770 Q51 V42
Re: If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 06 Oct 2012, 06:24
chigiwigi wrote:
For such large calculations, how do you find out that it's a right triangle? Thanks.
Did you read the replies in this thread? The question is whether we have sufficient information to determine whether it is a right triangle. The question is NOT whether it is a right triangle.

We know all 3 sides of the triangle. Therefore, we have sufficient information to determine whether it is a right triangle. It is NOT necessary to actually calculate whether it indeed is one.
Manager
Manager
avatar
Joined: 18 May 2010
Posts: 66
Re: If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 06 Oct 2012, 07:32
Ya, makes sense, thanks again.
Intern
Intern
avatar
Joined: 20 Dec 2018
Posts: 49
Re: If the length of side AB is 17, is triangle ABC a right tria  [#permalink]

Show Tags

New post 21 Dec 2018, 22:37
For a triangle to be isosceles triangle sides of the triangle must follow a2 + b2 = c2 where ‘c’ is the largest side of the triangle.
Statement 1. Here, we know the length of 2 sides but we are still unaware of the third side. So, we can use the above given equation. Hence, Insufficient.
Statement 2. We know the length of 2 sides of the triangle but we are unaware of the third side of the triangle. So, we can’t use the above equation. Hence, Insufficient.
Statement 1 & 2 together. Using the data given in the question statement and statement 1 and 2 together, we know all three sides of triangle.
1442 + 172 = 20736 + 289 = 21025 = 1452.
So, the triangle is a right triangle. Hence, Sufficient.
GMAT Club Bot
Re: If the length of side AB is 17, is triangle ABC a right tria   [#permalink] 21 Dec 2018, 22:37
Display posts from previous: Sort by

If the length of side AB is 17, is triangle ABC a right tria

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





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