Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 29 May 2017, 10:49

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# What is the perimeter of right triangle ABC? (1) AB = 5 (2)

Author Message
TAGS:

### Hide Tags

Manager
Joined: 24 Nov 2010
Posts: 210
Location: United States (CA)
Concentration: Technology, Entrepreneurship
Schools: Ross '15, Duke '15
Followers: 2

Kudos [?]: 83 [0], given: 7

What is the perimeter of right triangle ABC? (1) AB = 5 (2) [#permalink]

### Show Tags

01 Jun 2011, 07:07
4
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

51% (01:36) correct 49% (00:45) wrong based on 161 sessions

### HideShow timer Statistics

What is the perimeter of right triangle ABC?

(1) AB = 5
(2) AC = $$5\sqrt{2}$$
[Reveal] Spoiler: OA
Math Forum Moderator
Joined: 20 Dec 2010
Posts: 2013
Followers: 163

Kudos [?]: 1830 [1] , given: 376

Re: What is the perimeter of right triangle ABC? (1) AB = 5 (2) [#permalink]

### Show Tags

01 Jun 2011, 07:27
1
KUDOS
dreambeliever wrote:
What is the perimeter of right triangle ABC?
(1) AB = 5
(2) AC = $$5\sqrt{2}$$

(1) AB=5
We can't know the perimeter just by knowing one side of the right triangle.
Not Sufficient.

(2) $$AC=5\sqrt{2}$$
Not Sufficient.

Combining both;
We don't know which side is the hypotenuse.

If
$$AC=Hypotenuse=5\sqrt{2}$$
$$AB=5$$
$$BC=5$$
$$Perimeter=10+5\sqrt{2}$$

If
$$BC=hypotenuse$$
$$AB=5$$
$$AC=5\sqrt{2}$$
$$BC^2=AB^2+AC^2$$
$$BC^2=25+50$$
$$BC=\sqrt{75}=5\sqrt{3}$$
$$Perimeter=5+5\sqrt{2}+5\sqrt{3}$$

Not Sufficient.

Ans: "E"
_________________
Manager
Joined: 24 Nov 2010
Posts: 210
Location: United States (CA)
Concentration: Technology, Entrepreneurship
Schools: Ross '15, Duke '15
Followers: 2

Kudos [?]: 83 [0], given: 7

Re: What is the perimeter of right triangle ABC? (1) AB = 5 (2) [#permalink]

### Show Tags

01 Jun 2011, 07:32
OA is E.

But for some reason I remember learning in my High School that a right angled triangle ABC is right angled at B. If it was right angled at C, then the triangle will be referred to as ACB. Does that convention not apply to the GMAT?
Math Forum Moderator
Joined: 20 Dec 2010
Posts: 2013
Followers: 163

Kudos [?]: 1830 [0], given: 376

Re: What is the perimeter of right triangle ABC? (1) AB = 5 (2) [#permalink]

### Show Tags

01 Jun 2011, 07:53
dreambeliever wrote:
OA is E.

But for some reason I remember learning in my High School that a right angled triangle ABC is right angled at B. If it was right angled at C, then the triangle will be referred to as ACB. Does that convention not apply to the GMAT?

I would expect GMAT to explicitly tell me at which angle the triangle is right angled. I leave this for some experts to answer.
_________________
VP
Status: There is always something new !!
Affiliations: PMI,QAI Global,eXampleCG
Joined: 08 May 2009
Posts: 1331
Followers: 17

Kudos [?]: 254 [0], given: 10

Re: What is the perimeter of right triangle ABC? (1) AB = 5 (2) [#permalink]

### Show Tags

06 Jun 2011, 03:02
Since which angle is right angle has not been mentioned.

5(2^1/2 -1) < BC < 5(2^1/2 + 1).

perimeter can be anything is this region.

Thus E.
_________________

Visit -- http://www.sustainable-sphere.com/
Promote Green Business,Sustainable Living and Green Earth !!

Manager
Joined: 05 Jul 2010
Posts: 195
Followers: 1

Kudos [?]: 19 [0], given: 18

Re: What is the perimeter of right triangle ABC? (1) AB = 5 (2) [#permalink]

### Show Tags

06 Jun 2011, 18:57
yes, it is a trap. Don't assume anything on GMAT!
GMAT Tutor
Joined: 24 Jun 2008
Posts: 1179
Followers: 438

Kudos [?]: 1606 [0], given: 4

Re: What is the perimeter of right triangle ABC? (1) AB = 5 (2) [#permalink]

### Show Tags

07 Jun 2011, 11:53
dreambeliever wrote:
But for some reason I remember learning in my High School that a right angled triangle ABC is right angled at B. If it was right angled at C, then the triangle will be referred to as ACB. Does that convention not apply to the GMAT?

That's not a convention I've ever heard of. Don't assume that on the GMAT, at least.
_________________

GMAT Tutor in Toronto

If you are looking for online GMAT math tutoring, or if you are interested in buying my advanced Quant books and problem sets, please contact me at ianstewartgmat at gmail.com

Manager
Joined: 06 Jun 2013
Posts: 127
Location: India
Concentration: Finance, Economics
Schools: Tuck
GMAT 1: 640 Q49 V30
GPA: 3.6
WE: Engineering (Computer Software)
Followers: 0

Kudos [?]: 12 [0], given: 297

Re: What is the perimeter of right triangle ABC? (1) AB = 5 (2) [#permalink]

### Show Tags

28 Sep 2015, 08:59
since we do not know which angle is right angle, there are two possibilities. hence option is E.
Manager
Joined: 21 Aug 2012
Posts: 201
Concentration: General Management, Operations
Schools: HBS '19 (S)
GMAT 1: 740 Q49 V42
Followers: 0

Kudos [?]: 38 [0], given: 349

Re: What is the perimeter of right triangle ABC? (1) AB = 5 (2) [#permalink]

### Show Tags

25 Oct 2015, 07:30
Doesn't the 30-60-90 rule apply here?
Math Forum Moderator
Joined: 20 Mar 2014
Posts: 2644
Concentration: Finance, Strategy
Schools: Kellogg '18 (M)
GMAT 1: 750 Q49 V44
GPA: 3.7
WE: Engineering (Aerospace and Defense)
Followers: 128

Kudos [?]: 1478 [0], given: 789

Re: What is the perimeter of right triangle ABC? (1) AB = 5 (2) [#permalink]

### Show Tags

25 Oct 2015, 07:34
roopika2990 wrote:
Doesn't the 30-60-90 rule apply here?

Without knowing which angle is 90 degrees, how can you be sure of this? Additionally, why would you apply 30-60-90 rule here? Can you mention more about your thought process?
_________________

Thursday with Ron updated list as of July 1st, 2015: http://gmatclub.com/forum/consolidated-thursday-with-ron-list-for-all-the-sections-201006.html#p1544515
Inequalities tips: http://gmatclub.com/forum/inequalities-tips-and-hints-175001.html
Debrief, 650 to 750: http://gmatclub.com/forum/650-to-750-a-10-month-journey-to-the-score-203190.html

Senior Manager
Status: DONE!
Joined: 05 Sep 2016
Posts: 409
Followers: 3

Kudos [?]: 17 [0], given: 283

Re: What is the perimeter of right triangle ABC? (1) AB = 5 (2) [#permalink]

### Show Tags

20 Sep 2016, 08:25
E is correct. Here's why:

(1) AB = 5 --> NOT SUFFICIENT - you can't figure out perimeter of a triangle with only one side and no further information

(2) AC = 5√2 --> NOT SUFFICIENT - same as (1)

A,B,D are eliminated

Together (1) + (2) --> NOT SUFFICIENT - we don't know what is the hypotenuse and which is a side, therefore we don't know how to set up pythagorean theorem to find the missing side.
Re: What is the perimeter of right triangle ABC? (1) AB = 5 (2)   [#permalink] 20 Sep 2016, 08:25
Similar topics Replies Last post
Similar
Topics:
1 If the perimeter of right triangle ABC above is 3 + 3, what is the are 3 05 Jan 2016, 12:47
7 Is AB=10 the shortest side of triangle ABC? (1) The perimeter of ΔABC 4 22 Nov 2016, 08:03
7 In right triangle ABC above, the length of AB is 5*3^1/2. What is the 8 11 Jun 2016, 15:31
4 What is the perimeter of triangle ABC? 9 27 Apr 2015, 04:13
3 What is the perimeter of the isosceles right triangle ABC 10 16 Jul 2011, 11:42
Display posts from previous: Sort by