Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 04 May 2015, 09:52

### 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

# GMATPrep DS: Triangles and Angles

Author Message
TAGS:
Director
Joined: 12 Jul 2008
Posts: 518
Schools: Wharton
Followers: 16

Kudos [?]: 118 [0], given: 0

GMATPrep DS: Triangles and Angles [#permalink]  17 Aug 2008, 07:48
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
I got this question right, but just by thinking about the relationships of the different points on the triangle. Afterwards, I did this mathematically, and it took me a very long time with a large system of equations. Anyone have any thoughts on a quicker but mathematical way of doing this?
Attachments

GMATPrep 01.07.JPG [ 57.44 KiB | Viewed 772 times ]

Last edited by zonk on 17 Aug 2008, 08:49, edited 2 times in total.
Manager
Joined: 15 Jul 2008
Posts: 209
Followers: 3

Kudos [?]: 30 [1] , given: 0

Re: GMATPrep DS: Triangles and Angles [#permalink]  17 Aug 2008, 08:15
1
KUDOS
C.

Say angle PTR=x. Then angle PRT= 90-x (for right triangle PRT)

1) triangle QRS is isoceles. so angle rsq = angle rqs = (180-(90-x))/2 = 90/2 + x/2
Insufficient. for dtermining x as angle tsu is still unknown.

2) similarly will give you tus=tsu = (180-x)/2 = 180/2-x/2
Insufficient as with this alone rsq is unknown

Combine to get x= 180-rsq-tsu

So C
Intern
Joined: 07 Jan 2006
Posts: 49
Followers: 0

Kudos [?]: 3 [0], given: 0

Re: GMATPrep DS: Triangles and Angles [#permalink]  17 Aug 2008, 08:14
Unsure if my solution is right, give your thoughts.

Angle R + Angle T = Angle P = 90 degrees.

Angle R + 2A = 180 degrees (2A because QR = RS)
Angle T + 2B = 180 degrees (2B because ST = TU)

Angle R + 2A + Angle T + 2B = 360 degrees (1 triangle = 180 degrees)
90 degrees + 2A + 2B = 360 degrees
2A + 2B = 270 degrees

A + x + B = 180 degrees (given it's a straight line on the triangle)

Simplify 2A + 2B = 270 degrees by dividing by 2, which results: A + B = 135 degrees.

A + B + x = 180 degrees
135 degrees + x = 180 degrees
x = 45 degrees regardless what value A and B are as long as the given conditions are met.

Therefore, an answer can be found when both conditions are met.
Re: GMATPrep DS: Triangles and Angles   [#permalink] 17 Aug 2008, 08:14
Similar topics Replies Last post
Similar
Topics:
3 Triangle within a triangle and angles 11 06 Oct 2009, 11:15
1 GMATprep-angles 17 25 Jun 2008, 16:54
1 DS: triangle/angle (GMATPrep) 9 24 Oct 2007, 06:00
GMATPREP Triangle DS 6 20 Sep 2006, 17:58
DS: Rt. Angled Triangle 1 14 Sep 2006, 21:38
Display posts from previous: Sort by