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Isosceles Right Triangle

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by xcusemeplz2009 » Tue Oct 13, 2009 12:22 am
h is 16

h^2=2*a^2=>h=asqrt(2)

2a+h=16+16sqrt(2)

2a+sqrt(2)=16+16sqrt(2)

solving a=8*sqrt(2)
h=8*sqrt2*sqrt2=16
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by NikolayZ » Tue Oct 13, 2009 12:23 am
Hey there !

Since you have an isosceles triangle, its perimeter = 2x+y. ( 2 sides are x, and the hypotenuse is y)
so the perimeter is
16+16sqrt(2)=2x+y.
Also the hypotenuse equals xsqrt(2), since it is 45 degree isosceles right triangle.

16+16sqrt(2)=2x+xsqrt(2)

x= (16+16*sqrt(2)/(2+sqrt(2))
Then , hypotenuse will be x*sqrt(2)= (16*sqrt(2)+32)/(sqrt(2)+2)=16.
Last edited by NikolayZ on Tue Oct 13, 2009 8:52 am, edited 1 time in total.
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by heshamelaziry » Tue Oct 13, 2009 8:45 am
NikolayZ wrote:Hey there !

Since you have an isosceles triangle, its perimeter = 2x+y. ( 2 sides are x, and the hypotenuse is y)
so the perimeter is
16+16sqrt(2)=2x+y.
Also the hypotenuse equals xsqrt(2), since it is 45 degree isosceles right triangle.

16+16sqrt(2)=2x+xsqrt(2)

x= (16+16*sqrt(2)/(2+2*sqrt(2))
Then , hypotenuse will be x*sqrt(2)= (16*sqrt(2)+32)/(sqrt(2)+2)=16.
Last edited by heshamelaziry on Tue Oct 13, 2009 9:05 am, edited 2 times in total.
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by NikolayZ » Tue Oct 13, 2009 8:51 am
Sorry mate. "typo happens" (c) =) corrected.
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by heshamelaziry » Tue Oct 13, 2009 8:56 am
NikolayZ wrote:Sorry mate. "typo happens" (c) =) corrected.
I got it, finally. Thanks a lot.
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by NikolayZ » Tue Oct 13, 2009 9:13 am
heshamelaziry, truly there is a flaw in my solvent, because it is not consistent =(

so, right answer to my mind is

2x+x*sqrt(2)=16+16*sqrt(2)
x(2+sqrt(2)=16+16*sqrt(2)
x=(16+16*sqrt(2))/2+sqrt(2)
x*sqrt(2)=(16*sqrt(2)+16*sqrt(2)*sqrt(2))/2+sqrt(2)
==> since hte x*sqrt(2) is the hypotenuse (h)
then
h=(16*sqrt(2)+32)/2+sqrt(2)
factorizing 16 from the numerator we'll get
16(sqrt(2)+2)/(sqrt(2)+2)=16.
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by heshamelaziry » Tue Oct 13, 2009 9:25 am
NikolayZ wrote:heshamelaziry, truly there is a flaw in my solvent, because it is not consistent =(

so, right answer to my mind is

2x+x*sqrt(2)=16+16*sqrt(2)
x(2+sqrt(2)=16+16*sqrt(2)
x=(16+16*sqrt(2))/2+sqrt(2)
x*sqrt(2)=(16*sqrt(2)+16*sqrt(2)*sqrt(2))/2+sqrt(2)
==> since hte x*sqrt(2) is the hypotenuse (h)
then
h=(16*sqrt(2)+32)/2+sqrt(2)
factorizing 16 from the numerator we'll get
16(sqrt(2)+2)/(sqrt(2)+2)=16.

Thanks Dude :) I posted some problems form a GMATPrep test that I took. Maybe you like to take a shot at them. I posted them yesterday in an attachement.
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by kkpatel1 » Fri Nov 20, 2009 2:16 pm
heshamelaziry wrote:
NikolayZ wrote:heshamelaziry, truly there is a flaw in my solvent, because it is not consistent =(

so, right answer to my mind is

2x+x*sqrt(2)=16+16*sqrt(2)
x(2+sqrt(2)=16+16*sqrt(2)
x=(16+16*sqrt(2))/2+sqrt(2)
x*sqrt(2)=(16*sqrt(2)+16*sqrt(2)*sqrt(2))/2+sqrt(2)
==> since hte x*sqrt(2) is the hypotenuse (h)
then
h=(16*sqrt(2)+32)/2+sqrt(2)
factorizing 16 from the numerator we'll get
16(sqrt(2)+2)/(sqrt(2)+2)=16.

Where I am confused is:
When you set:
x*sqrt(2)=[(16*sqrt(2)+16*sqrt(2)*sqrt(2)]/2+sqrt(2)

why dont you multiply the bottom portion by sqrt(2) also, since the rule is, if you multiply one thing by something, you have to do it to everything!??

therefore shouldnt it be: h=(16*sqrt(2)+32)/2+2 ??
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