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.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Re: Everything About Triangles For GMAT. [#permalink]
24 Nov 2009, 09:49

awesome guide thanks! so there are other guides like this? I'm taking the GMAT tomorrow, I would love to have a quick but thorough review. can someone post the other guides? Thanks

Re: Everything About Triangles For GMAT. [#permalink]
24 Nov 2009, 10:06

manifestdestiny wrote:

awesome guide thanks! so there are other guides like this? I'm taking the GMAT tomorrow, I would love to have a quick but thorough review. can someone post the other guides? Thanks

Check out sticky threads in Math and Verbal forums. Pretty much everything important is collected up there.

Re: Math: Triangles [#permalink]
27 Dec 2009, 06:04

Expert's post

logan wrote:

Exceptional... a really well compiled data on triangles and their properties... the best part was to mention the problems from the official GMAT books.... +2

i think it would be worth mentioning the sine and cosine rules of triangles...

The law of sines (or Sine Rule):

If A, B and C are the angles made by the sides a= BC, b= CA & c= AB at the vertices of a triangle ABC, then according to the sine rule, (a/sin A) = (b/sin B) = (c/sin C)

The law of sines can be used to compute the remaining sides of a triangle when two angles and a side are known.

The law of cosines (or Cosine Rule) :

If A, B and C are the angles made by the sides a= BC, b= CA & c= AB at the vertices of a triangle ABC, then according to the cosine rule,

The law of cosines is useful for computing the third side of a triangle when two sides and their enclosed angle are known, and in computing the angles of a triangle if all three sides are known.

I withdrawn these rules as well as some other properties and formulas (there are plenty of them), as GMAT problems doesn't require knowing them for solving. No GMAT guide (as I know) mentions them in quant section. _________________

Re: Math: Triangles [#permalink]
14 Jan 2010, 15:34

A masterpiece Bunuel . Amazing summary of triangle proprties. Some Questions to have more clarity .

Are the medians equal in length in a scalene traingle ?

Does the centroid neccasarily have to be a center of circumcircle of a scalene triangle or in other words, does it mean that each triangle can be circumcircled ?

Re: Math: Triangles [#permalink]
14 Jan 2010, 16:01

Quote:

The SSA condition proves congruence if the angle is obtuse or right. In the case of the right angle (also known as the HL (Hypotenuse-Leg) condition or the RHS (Right-angle-Hypotenuse-Side) condition), we can calculate the third side and fall back on SSS.

Re: Math: Triangles [#permalink]
14 Jan 2010, 16:47

Expert's post

GMATMadeeasy wrote:

A masterpiece Bunuel . Amazing summary of triangle proprties. Some Questions to have more clarity .

Are the medians equal in length in a scalene traingle ?

Does the centroid neccasarily have to be a center of circumcircle of a scalene triangle or in other words, does it mean that each triangle can be circumcircled ?

Generally medians are not equal, so in scalene triangle medians are not equal.

Centroid is not the center of the circumscribed circle. (There was a typo in the text, edited.)

As for the circumscribed triangles: yes, any triangle can be circumscribed. _________________

Re: Math: Triangles [#permalink]
14 Mar 2010, 01:20

Bunuel, First of all thank you for the excellent compilation. I am using MGMAT books. And on this page I found many triangle concepts not covered in the book. Scary actually.

I wud like to know from other knowledgeable members, what they think about MGMAT books in terms of coverage of concepts?

Re: Math: Triangles [#permalink]
17 Jun 2010, 11:06

Quote:

Usually called "half of base times height", the area of a triangle is given by the formula below. • A=\frac{hb}{2}

Other formula: • A=\frac{P*r}{2}

• A=\frac{abc}{4R}

Where b is the length of the base, a and c the other sides; h is the length of the corresponding altitude; R is the Radius of circumscribed circle; r is the radius of inscribed circle; P is the perimeter

Just to clarify, is P the perimeter of the circle or the triangle?

Quote:

• For an isosceles triangle with given length of equal sides right triangle (included angle) has the largest area.

Will u elaborate on this please? I'm not sure how this works.

Thanks a lot of the summary, very complete and succinct! :D

gmatclubot

Re: Math: Triangles
[#permalink]
17 Jun 2010, 11:06