Lesson: Triangles - Part I

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Comment on Triangles - Part I

For these difficult questions with the answer choice 'E. Cannot be determined from the information above' - can I assume that for the most part these are 'trap' answer choices? (i.e. test makers know it's not easy so test takers are compelled to say that it cannot be determined using the info given)
gmat-admin's picture

I'm assuming you're referring to Data Sufficiency (DS) questions.

It's true that, for the very hard DS questions, it's more likely that the correct answer is A, B or D. HOWEVER, the problem with this strategy is that the computer adaptive nature of the GMAT ensures that everyone struggles. So, most people may feel that the correct answer to their tricky question will also be more likely to be A, B or D.

sir one more doubt
gmat-admin's picture

I have answered that question here: http://www.beatthegmat.com/another-ds-problem-t276598.html

Here's the link to the solution only: http://postimg.org/image/ri7ax9f8t/

Thank You sir

sir one more

Hi Brent,

Could you please explain solution to this answer. I am not able to figure it out?

Also, Are Similar & Identical triangles one & the same or do they differ? Also, in case of two identical triangles, are their sides equal or are they equal in proportion?
gmat-admin's picture

Question link: https://gmatclub.com/forum/in-the-figure-above-what-is-the-value-of-x-y-...

You bet!
Here's my solution: https://gmatclub.com/forum/in-the-figure-above-what-is-the-value-of-x-y-...

ASIDE: Identical triangles are . . . identical. Their corresponding angles are all equal AND their corresponding sides have equal length.

In SIMILAR triangles, the corresponding angles are equal, and the corresponding sides are PROPORTIONAL to each other.

Here's the video on similar triangles: https://www.gmatprepnow.com/module/gmat-geometry/video/872

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