Sector circle Test OG

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Sector circle Test OG

by isisalaska » Sun Jan 07, 2007 4:36 pm
A piece of land in the shape of a quarter circle with a 100 radius, which of the following is closest to the lengh in feet? answer is 357, why?
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by rajs.kumar » Mon Jan 08, 2007 8:15 am
What is the unit for the radius (100 what?)?

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Sector Circle Test OG

by isisalaska » Mon Jan 08, 2007 8:58 am
100 feet, sorry
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by Stacey Koprince » Tue Jan 09, 2007 6:01 pm
The problem asks for the "length" - are you asking for the perimeter of the quarter circle?
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Sector circle Test OG

by isisalaska » Thu Jan 11, 2007 5:02 pm
I guess is the periemter, the question used the word "lenght"
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by Stacey Koprince » Thu Jan 11, 2007 11:59 pm
I see. You might want to be cautious about using this source. If you typed the question in exactly as you found it, the question is too ambiguous to be a valid test question. It's best to study either from OG questions or from sources that spend the time and money to write questions that closely mimic the real test.

Anyway, you have three pieces to the perimeter: two radii (that's the plural of radius) and the quarter-circle arc. The radius is 100. The perimeter of the entire circle (if we had a full circle) would be 2*pi*r, or 200*pi. The arc of a quarter circle represents just one quarter of the total circumference, so (1/4) * (200pi) = 50pi.

The total perimeter of this shape, then, is 100 + 100 + 50pi, or approximately 357.

Which brings me to another reason this is not a valid test question: the test does not permit calculators, so on problems that use pi, you are not required to multiply by 3.14 - the answer choices just use pi. On the test, the correct answer choice would read "200 + 50pi" for a problem like this one. (Of course, they would use the actual symbol, not the word "pi.")

It's important to note this because, if you don't know how to get the correct answer, then you will want to examine the answer choices to see if you can find a way to eliminate wrong answers. And if you are studying answer choices that are not presented in the way they will be on the real test, then you won't be studying in an effective way.
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by ahumphries » Mon Oct 10, 2011 6:18 pm
The question was from the GMAT Practice Test 1. The question reads:
The figure shown represents a piece of land that is shaped like a quarter circle. If the land is enclosed by a fence, which of the following is closest to the length, in feet, of the fence.
The figure shows two sides (right triangle) with the length 100 ft each and the hypotenuse is an arc.
Answer is 357.


So you are saying that we will not have to calculate out pi on the actual test?