document.write( "Question 865836: how to find out the length of sides of an rectangle if the diagonal is given 15 cm and the perimeter is given 42 cm \n" ); document.write( "
Algebra.Com's Answer #521877 by josgarithmetic(39617)\"\" \"About 
You can put this solution on YOUR website!
x and y, the sides.\r
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\n" ); document.write( "\n" ); document.write( "\"2%28x%2By%29=42\" accounts for perimeter.
\n" ); document.write( "\"x%5E2%2By%5E2=15%5E2\" accounts for diagonal using Pythagorean Theorem - knowledge about rectangles.\r
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\n" ); document.write( "\n" ); document.write( "\"x%2By=21\", \"y=21-x\".
\n" ); document.write( "\"x%5E2%2B%2821-x%29%5E2=225\"
\n" ); document.write( "\"x%5E2%2B21%5E2-42x%2Bx%5E2=225\"
\n" ); document.write( "\"2x%5E2-42x%2B21%5E2-225=0\"
\n" ); document.write( "\"2x%5E2-42x%2B216=0\"
\n" ); document.write( "\"x%5E2-21x%2B108=0\"
\n" ); document.write( "\"%28x-12%29%28x-9%29=0\"
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\n" ); document.write( "\"highlight%28x=12%29\" or \"highlight%28x=9%29\". Plug these into the formula for y, and find y=9 or y=12.
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\n" ); document.write( "DIMENSIONS OF THE RECTANGLE: 9 and 12.
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