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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 350,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Re: If the length of side AB is 17, is triangle ABC a right triangle? [#permalink]
13 Oct 2009, 09:00

I don't see other possibility...

C should be correct... but would it be a GMAT question? i mean... calculating 144², 145² takes time... generally GMAT does not like spending too much time making calculations...

Re: If the length of side AB is 17, is triangle ABC a right triangle? [#permalink]
13 Oct 2009, 09:16

pierrealexandre77 wrote:

I don't see other possibility...

C should be correct... but would it be a GMAT question? i mean... calculating 144², 145² takes time... generally GMAT does not like spending too much time making calculations...

you may be correct than GMAT wont ask questions involving such numbers but then " HOPE FOR THE BEST,PREPARE FOR THE WORST"

Also 145^2 will be equal to 144^2 + (144*2 +1)----this is same as 144^2 plus 17^2

Re: If the length of side AB is 17, is triangle ABC a right triangle? [#permalink]
13 Oct 2009, 09:21

srini123 wrote:

looks like answer is D

I see that 17-square + 144-square = 145

so knowing that BC is 144 is sufficient

also knowing that 145 is sufficient by itself

but option 1 or 2 do not tell anything about the other side...the 3rd side of triangle... we can consider the 3rd (unknown side) as the one with maximum length e.g. 147 then also it will hold true by logic that sum of 2 sides should be more than the longest side....

Re: If the length of side AB is 17, is triangle ABC a right triangle? [#permalink]
13 Oct 2009, 10:49

srini123 wrote:

astermatrix must be right, it has to be C.

we need to know both the other sides

OA is C With all 3 sides you could see if a^2 + b^2 = c^2

As per above discussion, I agree it would be impossible in the 2 minutes provided to determine if this is a right triangle. However since this is a yes/no DS question we don't need to find an answer. Can we find an answer yes? Is this actually a right triangle? Who cares!

For those interested however... it is a right triangle.

Re: If the length of side AB is 17, is triangle ABC a right triangle? [#permalink]
13 Oct 2009, 11:09

2

This post received KUDOS

As asterixmatrix pointed out, this doesnt involve a whole lot of crazy calculation if you notice that 145^2 - 144^2 = (145-144)*(145+144) = 1*289 = 17^2.

You still need both those values to know whether it is a right triangle so answer should be [C].

Re: If the length of side AB is 17, is triangle ABC a right triangle? [#permalink]
29 Jun 2015, 10:43

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________

Re: If the length of side AB is 17, is triangle ABC a right triangle? [#permalink]
30 Jun 2015, 02:32

Expert's post

hogann 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.

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)

MBA Acceptance Rate by Country Most top American business schools brag about how internationally diverse they are. Although American business schools try to make sure they have students from...

McCombs Acceptance Rate Analysis McCombs School of Business is a top MBA program and part of University of Texas Austin. The full-time program is small; the class of 2017...

After I was accepted to Oxford I had an amazing opportunity to visit and meet a few fellow admitted students. We sat through a mock lecture, toured the business...