document.write( "Question 388566: Find the missing side length that will form an obtuse triangle with sides of length 8 and 10. \n" ); document.write( "
Algebra.Com's Answer #274928 by richard1234(7193)\"\" \"About 
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Suppose the missing side length is x. A triangle is obtuse if\r
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\n" ); document.write( "\n" ); document.write( "\"a%5E2+%2B+b%5E2+%3C+c%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "for some side lengths a, b, c (this is a result from the law of cosines). Therefore,\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2+%2B+8%5E2+%3C+10%5E2\" --> \"x+%3C+6\", but x must be greater than 2 due to the triangle inequality.\r
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\n" ); document.write( "\n" ); document.write( "Or, if x is the longest side, then\r
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\n" ); document.write( "\n" ); document.write( "\"8%5E2+%2B+10%5E2+%3C+x%5E2\" --> \"x+%3E+sqrt%28164%29\". x is less than 18 also because of the triangle inequality. Therefore, any real number in the sets (2, 6), (sqrt(164), 18) will make the triangle obtuse.
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