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Question Stats:
50% (01:54) correct
50% (00:37) wrong based on 2 sessions
Is area of triangle ABC greater than area of triangle DEF ? 1. The value of area of ABC is less than that of perimeter of DEF. 2. Angles of ABC = Angles of DEF. Source: GMAT Club Tests - hardest GMAT questions
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Is the answer C?
Have you considered that both statements will give you the answer 'No'?
I tried using two 3,4,5 triangles: Area=6, and P=12 so satisfies constraint in Stmt 1
Stmt 2: tells us that triangles are similar.
Together, the answer is NO -as in- Area of traingle ABC is not Greater then EFG.
Alternatively, i tried using two 6,8,10 triangles, which gave me Area=24 and P=24 so didnt satisfy stmt 1.
Also, the triangle in your method should've been "1, 1, root2" or "10, 10, 10root2" (the isoscelese right triangle) Think of a square cut in half diagonally. If a square has side 10, then 10x10=100 -> in half is 50.
Hope this helps and i hope i'm right!
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Ok, so the 10-10-20 thing was a typo. I got confused with that...
If you know both the triangles are similar, the area could be less than or greater than the perimeter. I see my mistake, thanks ryan.
But this only gives you info on the Area of ABC relative to the perimeter of ABC...statement (1) relates area ABC to perimeter DEF which we know nothing about.
3-4-5 P=12 Area=6
6-8-10 P=24 Area=24
9-12-15 P=36 Area=54
I think it is E after all.
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Let me clarify....
I considered the case that ABC and DEF are BOTH 3-4-5 triangles.
Look at that list you made a little more closely.
3-4-5 P=12 Area=6 ............area is smaller than P
6-8-10 P=24 Area=24 .......... area and P are equal
9-12-15 P=36 Area=54 ..........area is greater than P
Using two 3-4-5 triangles satisfies the constraint in Stmt1, and then when stmt 2 confirms that the triangles are similar, stmt 1&2 gives us the definitive answer 'NO' to the question if Area of ABC is greater then EFG - because the area is equal.
Another consideration.... let's take a 6-8-10 as ABC and 9-12-15 as DEF:
Stmt 1 is satisfied - Area ABC is less then P of DEF
Stmt 2 is satisfied - They are similar triangles
1&2 - together: Is area of ABC > DEF? .... NO it is not.
Make sense?
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shouldn't 2 angles be identical for triangles to be consider similar????
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GMAT2010 wrote: shouldn't 2 angles be identical for triangles to be consider similar???? yes,.... Stmt 2 says that the angles of ABC are the same as DEF.
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Sorry guys, the OE indeed had some typos. We'll edit it asap. Thanks everybody.
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I'm having some trouble understanding this question.
I see why it doesn't work by picking numbers, but I always have a hard time doing that on the test. I feel like I might miss one set of numbers which is why I try to solve algebraically.
So can someone conceptually explain this?
If the two triangles are similar, then their areas would be proportionate too. (right?)
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Would someone please take a moment and explain to me why this is E and not C? Once you know that the angles are the same AND that the perimeter is bigger don't you have enough information to say that ABC is in fact not bigger?
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mrcrescentfresh wrote: Would someone please take a moment and explain to me why this is E and not C? Once you know that the angles are the same AND that the perimeter is bigger don't you have enough information to say that ABC is in fact not bigger? The fact is that your reasoning works just for some types of triangles, while for others it doesn't. So, it must be E since both of them are too general. When I see question like these, it's a good idea not to waste too much time in experiments...the best idea is choosing E. Paolo
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michael127 wrote: Is area of triangle ABC greater than area of triangle DEF ? 1. The value of area of ABC is less than that of perimeter of DEF. 2. Angles of ABC = Angles of DEF. Source: GMAT Club Tests - hardest GMAT questions  I have an explanation)
1) Let's first try a 3:4:5 triangle. The area of a 3:4:5 triangle is 6 and the perimeter is 12. Now we go up to the question stem and we get NO.
Now that we have proven ABC is smaller than DEF we have to look for an instance where ABC is larger than DEF that would make statement 1) insufficient. If we make ABC a 2:2:2\sqrt{2} isosceles right triangle and DEF a 1:1:\sqrt{2} the area of ABC is 2 and the perimeter of DEF is 2 + \sqrt{2} (this makes the statement true).
We need to go to the question stem and plug this information in. The answer will be YES making statement 1 insufficient.
2) Statement 2 doesn't give us any information we can use.
Now the selections are C & E. Together the statements are not sufficient. So the answer is E.
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S1: Area of ABC = 0.5 (b) (h)
Perimeter of DEF = s1+s2+s3
0.5bh< s1+s2+s3
S2: not sufficient
Combining also there is no solution, so answer is E
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can someone give an example of where "The value of area of ABC is less than that of perimeter of DEF" and vice versa? Stmt1 is throwing me off!
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tiruraju wrote: its B sorry but B is not the answer, try again. 
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Got it wrong as well....... 
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Assume: AB = BC = 2, Angle ABC = 90; DE = EF = 1, Angle DEF = ABC = 90.
Area ABC = .5 * 2 * 2 = 2
Perimeter EDF = 1 + 1 + sqrt(2) > 2, but obviously Area ABD > Area DEF = 0.5.
The area of any triangle is the largest when it is a right triangle with both legs equal!
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simple geometry...the trick is in st 1: area of ABC is compared to perimeter of DEF..which does not lead us anywhere st2 itself does not help go for E
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stm 1 and 2 both can give definite no or definite yes for diffrent tringles. IMO E
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michael127 wrote: Is area of triangle ABC greater than area of triangle DEF ? 1. The value of area of ABC is less than that of perimeter of DEF. 2. Angles of ABC = Angles of DEF. Source: GMAT Club Tests - hardest GMAT questions B. can NEVER answer the question, because other two angles can vary and so do the sides, so -incorrect A. In given situation when the question is not limited to any specific angle consider the middle angle to be a right one, now even if it's a right angle 1/2 BC X AB = DE+EF+DF makes no sense ; incorrect E wins
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Hi Bunuel,
How do you eliminate A and C in this question?
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close
