document.write( "Question 1172080: A side and a diagonal of a parallelogram are 12 inches and 19 inches respectively. The angle between the diagonals, opposite the given side, is 124 degrees. Find the length of the other diagonal. \n" ); document.write( "
Algebra.Com's Answer #797109 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Use the law of cosines:\r\n" );
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document.write( "\"19%5E2=x%5E2%2B12%5E2-2%2812%29%28x%29cos%28124%5Eo%29\"\r\n" );
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document.write( "\"361=x%5E2%2B144-%2824x%29%28-0.5591929035%29\"\r\n" );
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document.write( "\"361=x%5E2%2B144%2B13.42062968x\"\r\n" );
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document.write( "\"x%5E2%2B144%2B13.42062968x-347.5793703=0\"\r\n" );
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document.write( "Solve by the quadratic formula:\r\n" );
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document.write( "\"x=9.476974162\"\r\n" );
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document.write( "We draw it with the other diagonal:\r\n" );
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document.write( "\"y%5E2=9.476974162%5E2%2B12%5E2-2%289.476974162%29%2812%29cos%2856%5Eo%29\"\r\n" );
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document.write( "\"y%5E2=106.626\"\r\n" );
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document.write( "\"y+=+10.326\"  <--answer (length of other diagonal.)\r\n" );
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document.write( "Edwin
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