Geometry - Topics under scope of the GMAT

shankar.ashwin wrote:Hi,

Would be helpful if a few of you could share scope of geometry covered in the GMAT. I see a lot of prep books covering topics like Incenter, circumcenter, orthocenter etc and also a lot of other theorems/ formulas especially covering triangles. But all the problems in the OG as well as the GMAT Prep questions hardly test these concepts. While I agree that knowing them may help us solve a few problems faster, I see it as one of the areas of diminishing returns.

Could experts/ fellow forum users share their thoughts ?

Thanks.

Areas

Cirles and its angular property

Volume

Triangles and their angles

Parallel Lines

are some of the topics tested! Mind you , they are not at a higher difficulty but general rules are tested!

I definitely would not bother worrying about incenters, orthocenters, and circumcenters unless I were absolutely destroying every single other type of question (including those on the verbal section) on the test, and even then I probably wouldn't bother. When in doubt, I would defer to the list of (very elementary) geometry topics that are outlined in the OG. For triangles, it looks like there's nothing more advanced than the Pythagorean theorem.

That said, I do think that some knowledge of topics that are slightly more advanced than those tested on the GMAT can add some perspective and depth to your understanding of the topics that ARE tested, which can be helpful. In some cases you can use the advanced theorems to check the plausibility of your answer, or increase your confidence in your approach, but as you say, these are areas of diminishing returns. It would be very rare that studying one of those topics would benefit someone more than studying a topic that is definitely tested directly and frequently on the GMAT.

Just out of curiosity, which prep books are you using that include these topics? Also, when you say they are "hardly tested" in the OG and GMAT Prep, does that mean you were able to find some questions that tested these concepts? If so, I'd be interested to see which ones you mean.

Thanks for the info Pete.

By hardly I meant I have NEVER seen official problems testing those topics. Wrong use of words I guess.


I saw a few problems from Manhattan GMAT archive which had a few questions based on the topics mentioned, centroid and all.
Was wondering geometry being a relatively difficult topic, why no official problems had these advanced topics covered. Was skeptical of studying all of them because the formulas for each kept piling up.

May be the archive does have a reference to these topic but if you see the actual Manhattan books they do not mention it

shankar.ashwin wrote:Thanks for the info Pete.

By hardly I meant I have NEVER seen official problems testing those topics. Wrong use of words I guess.


I saw a few problems from Manhattan GMAT archive which had a few questions based on the topics mentioned, centroid and all.
Was wondering geometry being a relatively difficult topic, why no official problems had these advanced topics covered. Was skeptical of studying all of them because the formulas for each kept piling up.

Yeah! Haven't seen them in the guides.

venmic wrote:May be the archive does have a reference to these topic but if you see the actual Manhattan books they do not mention it

shankar.ashwin wrote:Hi,

Would be helpful if a few of you could share scope of geometry covered in the GMAT. I see a lot of prep books covering topics like Incenter, circumcenter, orthocenter etc and also a lot of other theorems/ formulas especially covering triangles. But all the problems in the OG as well as the GMAT Prep questions hardly test these concepts. While I agree that knowing them may help us solve a few problems faster, I see it as one of the areas of diminishing returns.

Could experts/ fellow forum users share their thoughts ?

Thanks.

I wouldn't worry about the topics to which you're referring. Most GMAT geometry questions require knowledge of only the most basic formulas (area of a triangle, circumference of a circle, etc.). Even the Pythagorean theorem isn't needed much, since the GMAT tends to use triples (3-4-5, etc.) and special triangles (45-45-90, 30-60-90).