document.write( "Question 85290: Find the missing side in the triangle using pythagorean theorem, give answer as a simplified radical\r
\n" ); document.write( "\n" ); document.write( "x,2x,15\r
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Algebra.Com's Answer #61480 by bucky(2189)\"\" \"About 
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Given: A triangle having the sides x, 2x, and 15. The problem says to use the Pythagorean
\n" ); document.write( "theorem to find the value of x. (This means that the given triangle is a right triangle
\n" ); document.write( "since the Pythagorean theorem only applies to right triangles.)
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\n" ); document.write( "The way this problem is stated, there are two possible answers depending on which side you
\n" ); document.write( "assume is the long side (hypotenuse). The side x cannot be the hypotenuse because it is shorter
\n" ); document.write( "than the side 2x. Therefore, there are two possibilities for the hypotenuse. Either the
\n" ); document.write( "hypotenuse is 2x or it is 15.
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\n" ); document.write( "Let's first assume that the hypotenuse is 2x. That means that one leg is x and the other is
\n" ); document.write( "15.
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\n" ); document.write( "By the Pythagorean theorem, square each of the legs, add these two squares, and set that
\n" ); document.write( "sum equal to the square of the hypotenuse. In equation form this is:
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\n" ); document.write( "\"x%5E2+%2B+15%5E2+=+%282x%29%5E2\"
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\n" ); document.write( "The square of 15 is 225 and \"%282x%29%5E2+=+4x%5E2\". Substitute these into the equation and
\n" ); document.write( "it becomes:
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\n" ); document.write( "\"x%5E2+%2B+225+=+4x%5E2\"
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\n" ); document.write( "Subtract \"x%5E2\" from both sides and the equation becomes:
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\n" ); document.write( "\"225+=+3x%5E2\"
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\n" ); document.write( "Divide both sides by 3 and it further reduces to:
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\n" ); document.write( "\"75+=+x%5E2\"
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\n" ); document.write( "Next take the square root of both sides and you get:
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\n" ); document.write( "\"x+=+sqrt%2875%29+=+sqrt%2825%2A3%29+=+sqrt%2825%29%2Asqrt%283%29+=+5%2Asqrt%283%29\"
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\n" ); document.write( "Notice the steps involved in simplifying the radical to get \"x+=+5%2Asqrt%283%29\" as the
\n" ); document.write( "first possible answer.
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\n" ); document.write( "But we said that the possibility exists that the hypotenuse is 15. In this case the two
\n" ); document.write( "legs are x and 2x. Applying the Pythagorean theorem to this problem results in:
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\n" ); document.write( "\"x%5E2+%2B+%282x%29%5E2+=+15%5E2\"
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\n" ); document.write( "Again substituting for \"%282x%29%5E2\" and for \"15%5E2\" changes the equation to:
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\n" ); document.write( "\"x%5E2+%2B+4x%5E2+=+225\"
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\n" ); document.write( "Adding the two term on the left side results in:
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\n" ); document.write( "\"5x%5E2+=+225\"
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\n" ); document.write( "Divide both sides by 5 to get:
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\n" ); document.write( "\"x%5E2+=+45\"
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\n" ); document.write( "Then take the square root of both sides and you end up with:
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\n" ); document.write( "\"x+=+sqrt%2845%29+=+sqrt%289%2A5%29+=+sqrt%289%29%2Asqrt%285%29+=+3%2Asqrt%285%29\"
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\n" ); document.write( "This is the second possible answer \"x+=+3%2Asqrt%285%29\"
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\n" ); document.write( "Which answer fits is dependent on which side is presumed to be the hypotenuse.
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\n" ); document.write( "Hope this helps you to understand the problem and why the possibility exists for two answers.
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