|
Author |
Message |
|
TAGS:
|
|
|
Intern
Joined: 03 Aug 2010
Posts: 10
|
Re: Math: Polygons
[#permalink]
Show Tags
 23 Aug 2010, 19:52
Thank You.Excellent post.
_________________
Welcome to my paintings website - Wholesale Art Mall.
|
|
|
|
|
|
Senior Manager
Joined: 23 May 2010
Posts: 311
|
Re: Math: Polygons
[#permalink]
Show Tags
24 Aug 2010, 01:48
mainhoon wrote: Thanks for the post Bunuel. I have a doubt. Do the diagonals bisect each other in a trapezoid? Bunuel wrote: logan wrote: nice post, as usual, Bunuel...
i m becoming a great fan of ur posts...
a small suggestion from my side... in the explanation of trapezoid, the diagram shows bases as a and b and height as h, but in the formula for area you considered different variables, though this doesn't point out any mistake in the formula, it would be clear if u considered the same variables...
with such wonderful posts gmatclub can start its own quant book i suppose.... wow...
i almost forgot.... kudossssssssss..... +1 Thanks. You are right, changed the variables as you suggested. +1 for good suggestion. As for the quant book: actually we are working on our very own GMAT MATH BOOK. Of course much work has to be done till completing it: this topic isn't finished yet, we are working on Number Theory, other topics are waiting... But at the end we'll hope to get comprehensive guide to the quant topics of GMAT. dear just see the link in Bunuel signatures ....the geometry notes(like other notes )are amazing ....take a print ...read one ce a day ... in a week you will be on top of all the properties
|
|
|
|
|
|
Intern
Joined: 03 Aug 2010
Posts: 10
|
Re: Math: Polygons
[#permalink]
Show Tags
29 Aug 2010, 22:47
Excellent post. thanks. You are amazing.
_________________
Welcome to my paintings website - Wholesale Art Mall.
|
|
|
|
|
|
Manager
Joined: 16 Feb 2010
Posts: 189
|
Re: Math: Polygons
[#permalink]
Show Tags
30 Aug 2010, 14:23
excellent ! - thank you +1
|
|
|
|
|
|
Manager
Joined: 15 Apr 2010
Posts: 135
|
Re: Math: Polygons
[#permalink]
Show Tags
05 Oct 2010, 11:59
Thanks Bunuel for such comprehensive notes.... 
|
|
|
|
|
|
Manager
Joined: 27 May 2008
Posts: 107
|
Re: Math: Polygons
[#permalink]
Show Tags
07 Oct 2010, 20:46
Hi Bunuel,
Nice post can you extend this by including solid figures also.
|
|
|
|
|
|
Retired Moderator
Joined: 02 Sep 2010
Posts: 775
Location: London
|
Re: Math: Polygons
[#permalink]
Show Tags
08 Oct 2010, 00:33
|
|
|
|
|
|
Manager
Joined: 01 Nov 2010
Posts: 147
Location: Zürich, Switzerland
|
Re: Math: Polygons
[#permalink]
Show Tags
27 Nov 2010, 06:45
One more masterpiece from Bunuel...... Kudos...!!
|
|
|
|
|
|
Manager
Joined: 30 Aug 2010
Posts: 89
Location: Bangalore, India
|
Re: Math: Polygons
[#permalink]
Show Tags
02 Feb 2011, 00:32
Pkit wrote: Bunuel,
you may add this to your post.
How many diagonals has a polygon with 25 sides?
the formula is:
Number of diagonals in a given polygon is =\(\frac{n*(n-3)}{2}\), where n – is the number of sides.
simple example in a square number of diagonals is =\(\frac{4*(4-3)}{2}=2\) The below is the concept used to derive the above formula for Number of diagonals . As we know, to make a diagonal (a line), we need 2 (a pair of) points. if i have n sided plygon, i need to select different par of points. This can be doen in \(nc2\) ways but thease pairs include all the sides also. hence subtract the number of sides (\(n\)), whiich are not diagonals, from the above ==> \(The Number of diagonals\) is ==> \(nc2-n\) ==> \(\frac{n(n-1)}{2} - n\) ==> \(\frac{(n^2-3n)}{2}\) ==> \(\frac{n(n-3)}{2}\) Regards, Murali. Kudos?
|
|
|
|
|
|
Manager
Joined: 18 Aug 2010
Posts: 83
|
Re: Math: Polygons
[#permalink]
Show Tags
08 Feb 2011, 01:14
RenukaD wrote: Great post , as always!, by Bunuel. Thanks Great post !!!  THANK YOU + Kudo
|
|
|
|
|
|
Manager
Affiliations: The Earth organization, India
Joined: 25 Dec 2010
Posts: 187
WE 1: SAP consultant-IT 2 years
WE 2: Entrepreneur-family business 2 years
|
Re: Math: Polygons
[#permalink]
Show Tags
27 Jun 2011, 09:22
Hi, Super awesome post by the genius again.  One small doubt. if a DS question talks about a parallelogram and then goes on to say that the diagonals are equal. Does it imply we have a rectangle ? Further the post says that should the diagonals of a parallelogram be equal and the angles be bisected by it, its a square. But I think this will happen in case of both a rect and a square ?
_________________
Cheers !!
Quant 47-Striving for 50
Verbal 34-Striving for 40
|
|
|
|
|
|
Manager
Affiliations: The Earth organization, India
Joined: 25 Dec 2010
Posts: 187
WE 1: SAP consultant-IT 2 years
WE 2: Entrepreneur-family business 2 years
|
Re: Math: Polygons
[#permalink]
Show Tags
27 Jun 2011, 09:24
Hi, Super awesome post by the genius again. One small doubt. if a DS question talks about a parallelogram and then goes on to say that the diagonals are equal. Does it imply we have a rectangle ? Further the post says that should the diagonals of a parallelogram be equal and the angles be bisected by it, its a square. But I think this will happen in case of both a rect and a square ?
_________________
Cheers !!
Quant 47-Striving for 50
Verbal 34-Striving for 40
|
|
|
|
|
|
Intern
Joined: 03 Mar 2011
Posts: 16
WE: Sales (Hospitality and Tourism)
|
Re: Math: Polygons
[#permalink]
Show Tags
02 Jul 2011, 05:14
many thanks for this !
|
|
|
|
|
|
Intern
Joined: 24 Apr 2011
Posts: 1
|
Re: Math: Polygons
[#permalink]
Show Tags
16 Jul 2011, 00:22
Great post....Thanks
|
|
|
|
|
|
Manager
Joined: 28 May 2011
Posts: 170
Location: United States
Concentration: General Management, International Business
GPA: 3.6
WE: Project Management (Computer Software)
|
Re: Math: Polygons
[#permalink]
Show Tags
17 Jul 2011, 05:22
great post..thanks Bunuel
_________________
-------------------------------------------------------------------------------------------------------------------------------
http://gmatclub.com/forum/a-guide-to-the-official-guide-13-for-gmat-review-134210.html
-------------------------------------------------------------------------------------------------------------------------------
|
|
|
|
|
|
Manager
Joined: 06 Apr 2011
Posts: 54
Location: India
|
Re: Math: Polygons
[#permalink]
Show Tags
23 Jul 2011, 20:21
another awesome post... thanks Benuel
_________________
Regards,
Asher
|
|
|
|
|
|
Intern
Joined: 03 Nov 2011
Posts: 9
|
Re: Math: Polygons
[#permalink]
Show Tags
10 Nov 2011, 01:23
Many thanks!! could find the info only there!! highly appreciate 
|
|
|
|
|
|
Intern
Joined: 27 Nov 2011
Posts: 1
|
Re: Math: Polygons
[#permalink]
Show Tags
03 Dec 2011, 13:25
Amazing post, thank you!
|
|
|
|
|
|
Intern
Joined: 30 Oct 2011
Posts: 11
|
Re: Math: Polygons
[#permalink]
Show Tags
04 Jan 2012, 00:28
Bunuel, thanks once again for your great work.
Although this has already been asked in some form on this thread, I would like to ask you to add a set of sufficient properties that would allow a GMAT taker to determine the type of a quad. I find that this aspect is very moot in the Manhattan Geometry guide. The set of properties should be as minimal as possible in order to be useful on DS questions. For example (please correct me if those properties are not true),
Parallelogram
Given a quad, if its opposite sides are parallel then it is a parallelogram.
Given a quad, it its opposite sides are equal then it is a parallelogram.
Rhombus
Given a quad, if its diagonals are perpendicular bisectors then it is a rhombus.
Square
Given a quad, if its sides are equal then it is a square.
Given a quad, if its angles are equal (90 degrees) then it is a square.
Given a quad, if its diagonals are equal then it is a square.
Thanks in advance.
|
|
|
|
|
|
Intern
Status: Active
Joined: 30 Jun 2012
Posts: 38
Location: India
|
Re: Math: Polygons
[#permalink]
Show Tags
28 Oct 2012, 07:14
Regular polygon's area can be calculated,other polygon's area can also be calculated using graph coordinates,but i have heard that polygon's area can be calculated using sides and external angles is it true?if it is what is the method?
_________________
Thanks and Regards!
P.S. +Kudos Please! in case you like my post.
|
|
|
|
|
|
|
Re: Math: Polygons &nbs
[#permalink]
28 Oct 2012, 07:14
|
|
|
|
|
Go to page
Previous
1 2 3
Next
[ 48 posts ]
|
|
|
|
|
|
close
