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by rijul007 » Tue Nov 01, 2011 10:11 am
hypotenuse = a
each side = a/root(2)

Perimeter of rt isosceles triangle = a + 2a/root(2) = a+a*root(2) = 16+16*root(2)


so hypotenuse = 16
Option B
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by gmatblood » Tue Nov 01, 2011 10:19 am
Is it 8ROOT2 ?
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by saketk » Tue Nov 01, 2011 11:03 am
The easiest way is to plug the answer choices [ remember to start with smart choices ]


2a^2 = b^2 (b is the hypotenuse)

or, a = b/sqrt(2) = b*sqrt(2)/2 -- THIS IS OUR MAIN EXPRESSION.

By smart choices I mean -- look at the perimeter.. It has root2 in it. So start with choices where you don't have ROOT(2) because our expression above has already got one.

Put the choices and see whether the value satisfies this equation .. 2a+b = 16+16*sqrt(2).

this will take 45-60 secs.

hth

IMO [spoiler](16) [/spoiler] the correct answer.
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by LalaB » Wed Nov 02, 2011 1:06 am
2a^2=h^2
a=h/sqroot2

2*h/sqroot2+h=16+16*sqroot2

sqroot2*h+h=16+16*sqroot2
h*(sqroot2+1)=16(sqroot2+1)

h=16
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by vaibhavgupta » Wed Nov 02, 2011 2:22 pm
fbgeoff wrote:Image
IMO D

WHTS the OA?
If OA is A, IMO B
If OA is B, IMO C
If OA is C, IMO D
If OA is D, IMO E
If OA is E, IMO A

FML!! :/
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by neelgandham » Wed Nov 02, 2011 2:39 pm
Let the length of the perpendicular sides be a, Hypotenuse = a*Square root(2) = ?

16 + 16*(Square root(2)) = a+a+(a*Square root(2))

16*(1+(Square root(2)) = a*Square root(2)* (1+(Square root(2))

16 = a*Square root(2) = Hypotenuse !

IMO : B

vaibhavgupta - I reckon you calculated the side, and not the Hypotenuse
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by fbgeoff » Wed Nov 02, 2011 7:33 pm
Correct answer according to the GMATPrep is B
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by vaibhavgupta » Thu Nov 03, 2011 1:28 am
neelgandham wrote:Let the length of the perpendicular sides be a, Hypotenuse = a*Square root(2) = ?

16 + 16*(Square root(2)) = a+a+(a*Square root(2))

16*(1+(Square root(2)) = a*Square root(2)* (1+(Square root(2))

16 = a*Square root(2) = Hypotenuse !

IMO : B

vaibhavgupta - I reckon you calculated the side, and not the Hypotenuse
:?

Hmm.. will keep this in mind, thanks :)
If OA is A, IMO B
If OA is B, IMO C
If OA is C, IMO D
If OA is D, IMO E
If OA is E, IMO A

FML!! :/
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