Difference between revisions of "2002 AMC 10B Problems/Problem 22"

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== Problem 22 ==
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== Problem==
  
 
Let <math>\triangle{XOY}</math> be a right-triangle with <math>m\angle{XOY}=90^\circ</math>. Let <math>M</math> and <math>N</math> be the midpoints of the legs <math>OX</math> and <math>OY</math>, respectively. Given <math>XN=19</math> and <math>YM=22</math>, find <math>XY</math>.
 
Let <math>\triangle{XOY}</math> be a right-triangle with <math>m\angle{XOY}=90^\circ</math>. Let <math>M</math> and <math>N</math> be the midpoints of the legs <math>OX</math> and <math>OY</math>, respectively. Given <math>XN=19</math> and <math>YM=22</math>, find <math>XY</math>.
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\sqrt{4x^2+4y^2}&=\boxed{\mathrm{(B) \ } 26}
 
\sqrt{4x^2+4y^2}&=\boxed{\mathrm{(B) \ } 26}
 
\end{align*}</cmath>
 
\end{align*}</cmath>
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==See Also==
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{{AMC10 box|year=2002|ab=B|num-b=21|num-a=23}}

Revision as of 01:42, 5 June 2011

Problem

Let $\triangle{XOY}$ be a right-triangle with $m\angle{XOY}=90^\circ$. Let $M$ and $N$ be the midpoints of the legs $OX$ and $OY$, respectively. Given $XN=19$ and $YM=22$, find $XY$.

$\mathrm{(A) \ } 24\qquad \mathrm{(B) \ } 26\qquad \mathrm{(C) \ } 28\qquad \mathrm{(D) \ } 30\qquad \mathrm{(E) \ } 32$

Solution

Let $OM=MX=x$ and $ON=NY=y$. By the Pythagorean Theorem, $x^2+4y^2=484$ and $4x^2+y^2=361$ We wish to find $\sqrt{4x^2+4y^2}$. So, we add the two equations, multiply by $\frac{4}{5}$, and take the square root. \begin{align*} 5x^2+5y^2&=845\\ 4x^2+4y^2&=676\\ \sqrt{4x^2+4y^2}&=\boxed{\mathrm{(B) \ } 26} \end{align*}

See Also

2002 AMC 10B (ProblemsAnswer KeyResources)
Preceded by
Problem 21
Followed by
Problem 23
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 10 Problems and Solutions