document.write( "Question 209995: If the Perimeter of a rectangle is 40 and the diagonal is 12 find the area. \n" ); document.write( "
Algebra.Com's Answer #159160 by Tanzem(4)\"\" \"About 
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2(l+b)=40
\n" ); document.write( "l+b=20 (squaring both the sides)
\n" ); document.write( "l2+b2+lb=400....1\r
\n" ); document.write( "\n" ); document.write( "Now diagonal= 12
\n" ); document.write( "its right angle triangle.
\n" ); document.write( "l2+b2= 144......2\r
\n" ); document.write( "\n" ); document.write( "substituting 2 in 1 we get\r
\n" ); document.write( "\n" ); document.write( "144+lb=400
\n" ); document.write( "lb=256 that is area
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