document.write( "Question 1067836: the sum of length, breadth and depth of a cuboid is 19 cm and the length of diagonal is 11 cm. find the surface area of the cuboid. \n" ); document.write( "
Algebra.Com's Answer #683024 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
Let \"x\", \"y\" and \"z\" be the length, breadth and depth of the cuboid.
\n" ); document.write( "\"x%2By%2Bz=19\" and
\n" ); document.write( "\"sqrt%28x%5E2%2By%5E2%2Bz%5E2%29=11\" ---> \"x%5E2%2By%5E2%2Bz%5E2=121\"
\n" ); document.write( "are out clues,
\n" ); document.write( "and of course \"system%28x%3E0%2Cy%3E0%2Cz%3E0%29\"
\n" ); document.write( "\"%28x%2By%2Bz%29%5E2=19%5E2\"--->\"x%5E2%2By%5E2%2Bz%5E2%2B2%28x%2By%2Bz%29=361\"
\n" ); document.write( "\"system%28x%5E2%2By%5E2%2Bz%5E2%2B2%28x%2By%2Bz%29=361%2Cx%5E2%2By%5E2%2Bz%5E2=121%29\"--->\"22%28x%2By%2Bz%29=361-121=highlight%28240%29\"
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\n" ); document.write( "and yes, there are other options beyond {x,y,z} = {6,6,7} ,
\n" ); document.write( "but none with three integers, and the options fall in a narrow range.around
\n" ); document.write( "You can make \"z=19-x-y\",
\n" ); document.write( "substitute into \"x%5E2%2By%5E2%2Bz%5E2=121\"
\n" ); document.write( "to get an equation of degree 2 in \"x\" and \"y\" .
\n" ); document.write( "For the equation to have a solution for \"y\" ,
\n" ); document.write( "you need \"17%2F3%3Cx%3C7\" .
\n" ); document.write( "To figure out if there would be another solution with integers,
\n" ); document.write( "I searched on line for \"Pythagorean quadruples\",
\n" ); document.write( "sets of 4 whole numbers, \"matrix%281%2C7%2Ca%2C%22%2C%22%2Cb%2C%22%2C%22%2Cc%2C%22%2C%22%2Cd%29\" ,
\n" ); document.write( "such that \"a%5E2%2Bb%5E2%2Bc%5E2=d%5E2\" .
\n" ); document.write( "The lists are given with the numbers \"matrix%281%2C7%2Ca%2C%22%2C%22%2Cb%2C%22%2C%22%2Cc%2C%22%2C%22%2Cd%29\"
\n" ); document.write( "in such order that \"a%3C=b%3C=c%3Cd\" ,
\n" ); document.write( "so you only have to the first few
\n" ); document.write( "to realize that the only two ending in 11 are
\n" ); document.write( "2, 6, 9, 11 and 6, 6, 7, 11 .
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