Last visit was: Mon Sep 14, 2026 1:05 pm It is currently Mon Sep 14, 2026 1:05 pm
Home
Messages
Tests
Schools
Events
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
505-555 (Easy)|   Geometry|      
User avatar
danzig
User avatar
Joined: 11 Aug 2012
Last visit: 07 Nov 2014
Posts: 103
Own Kudos:
400
 [8]
Given Kudos: 16
Schools: HBS '16 Stanford '16
Schools: HBS '16 Stanford '16
Posts: 103
Kudos: 400
 [8]
In the triangle above, DC is parallel to AB. What is the len Updated on: Sun Mar 05, 2023 8:46 am
Originally posted by danzig on Thu Jul 11, 2013 10:49 am.
Last edited by Bunuel on Sun Mar 05, 2023 8:46 am, edited 2 times in total.
Edited the question.
Kudos
Add Kudos
8
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

15% (low)

Question Stats:

75% (01:00) correct 25% (01:05) wrong based on 261 sessions

History

Date
Time
Result
Not Attempted Yet

In the triangle above, DC is parallel to AB. What is the length of DC?

(1) AB = 14
(2) EC = CB

Show Spoiler
Attachment:
Triangle.jpg
Triangle.jpg [ 13.9 KiB | Viewed 5652 times ]
Please, confirm whether my solution is correct. If we consider both statements, we can notice that triangles AEB and DEC are the "same" triangle, except for the size. In other words, both have the same angles. Therefore, the relationship between any of two of their sides must be the same. Then,

\(\frac{14}{EB} = \frac{DC}{EC}\)

But we know that EC = 0.5*EB

Then: DC = 7

My answer is the OA.

Is it valid what I have done? I remember that I learned this in high school :s.
ShowHide Answer
Official Answer
C
Pure algebraic questions like this one are no longer part of the GMAT Data Sufficiency syllabus.
For relevant Data Sufficiency questions, please check the Data Sufficiency forum:
Data Sufficiency Forum
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 14 Sep 2026
Posts: 113,508
Own Kudos:
841,285
 [3]
Given Kudos: 111,515
Products:
GMAT Club Tests
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 113,508
Kudos: 841,285
 [3]
In the triangle above, DC is parallel to AB. What is the len Thu Jul 11, 2013 11:21 am
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
danzig


In the triangle above, DC is parallel to AB. What is the length of DC?

(1) AB = 14
(2) EC = CB

Please, confirm whether my solution is correct. If we consider both statements, we can notice that triangles AEB and DEC are the "same" triangle, except for the size. In other words, both have the same angles. Therefore, the relationship between any of two of their sides must be the same. Then,

\(\frac{14}{EB} = \frac{DC}{EC}\)

But we know that EC = 0.5*EB

Then: DC = 7

My answer is the OA.

Is it valid what I have done? I remember that I learned this in high school :s.
Show more

Yes, your solution is correct.

Else you can notice that DC is the midsegment (a line segment joining the midpoints of two sides of a triangle). The midsegment is always half the length of the third side, thus DC=AB/2=7.

Answer: C.

Similar questions to practice:
https://gmatclub.com/forum/if-be-cd-and ... 27060.html
https://gmatclub.com/forum/if-b-is-the- ... 27104.html
https://gmatclub.com/forum/ds-geometry- ... 28687.html
https://gmatclub.com/forum/in-triangle- ... 82671.html
https://gmatclub.com/forum/abcd-is-quad ... 31462.html

Hope it's clear.
User avatar
Urvasi
User avatar
Joined: 27 Feb 2022
Last visit: 24 Apr 2023
Posts: 11
Own Kudos:
7
Given Kudos: 30
Posts: 11
Kudos: 7
In the triangle above, DC is parallel to AB. What is the len Sun Mar 05, 2023 7:36 am
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
danzig
Attachment:
Triangle.jpg
In the triangle above, DC is parallel to AB. What is the length of DC?

(1) AB = 14
(2) EC = CB

Please, confirm whether my solution is correct. If we consider both statements, we can notice that triangles AEB and DEC are the "same" triangle, except for the size. In other words, both have the same angles. Therefore, the relationship between any of two of their sides must be the same. Then,

\(\frac{14}{EB} = \frac{DC}{EC}\)

But we know that EC = 0.5*EB

Then: DC = 7

My answer is the OA.

Is it valid what I have done? I remember that I learned this in high school :s.

Yes, your solution is correct.

Else you can notice that DC is the midsegment (a line segment joining the midpoints of two sides of a triangle). The midsegment is always half the length of the third side, thus DC=AB/2=7.

Answer: C.

Similar questions to practice:
https://gmatclub.com/forum/if-be-cd-and ... 27060.html
https://gmatclub.com/forum/if-b-is-the- ... 27104.html
https://gmatclub.com/forum/ds-geometry- ... 28687.html
https://gmatclub.com/forum/in-triangle- ... 82671.html
https://gmatclub.com/forum/abcd-is-quad ... 31462.html

Hope it's clear.
Show more

Is it ok to infer that DC is the mid segment? DC can be parallel without being mid segment; In that case the answer will change
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 14 Sep 2026
Posts: 113,508
Own Kudos:
841,285
Given Kudos: 111,515
Products:
GMAT Club Tests
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 113,508
Kudos: 841,285
In the triangle above, DC is parallel to AB. What is the len Sun Mar 05, 2023 8:51 am
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Urvasi
Bunuel
danzig


In the triangle above, DC is parallel to AB. What is the length of DC?

(1) AB = 14
(2) EC = CB

Please, confirm whether my solution is correct. If we consider both statements, we can notice that triangles AEB and DEC are the "same" triangle, except for the size. In other words, both have the same angles. Therefore, the relationship between any of two of their sides must be the same. Then,

\(\frac{14}{EB} = \frac{DC}{EC}\)

But we know that EC = 0.5*EB

Then: DC = 7

My answer is the OA.

Is it valid what I have done? I remember that I learned this in high school :s.

Yes, your solution is correct.

Else you can notice that DC is the midsegment (a line segment joining the midpoints of two sides of a triangle). The midsegment is always half the length of the third side, thus DC=AB/2=7.

Answer: C.

Similar questions to practice:
https://gmatclub.com/forum/if-be-cd-and ... 27060.html
https://gmatclub.com/forum/if-b-is-the- ... 27104.html
https://gmatclub.com/forum/ds-geometry- ... 28687.html
https://gmatclub.com/forum/in-triangle- ... 82671.html
https://gmatclub.com/forum/abcd-is-quad ... 31462.html

Hope it's clear.

Is it ok to infer that DC is the mid segment? DC can be parallel without being mid segment; In that case the answer will change
Show more

We can deduce that DC is the midsegment only after we combine the statements. At that point we know that C is the midpoint of EB and DC is parallel to AB, therefore, DC must be the midsegment. When considering the statements alone DC may or may not be the midsegment.
Moderator:
Bunuel
Math Expert
113508 posts