document.write( "Question 1077822: The altitude of a rectangle is 20% less than the base and the perimeter is 18cm.Find the dimensions of the rectangle \n" ); document.write( "

Algebra.Com's Answer #692333 by josmiceli(19441) $\"\"$ $\"About$

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Let the altitude = $\"+a+\"$ cm
\n" ); document.write( "Let the base = $\"+b+\"$ cm
\n" ); document.write( "------------------------
\n" ); document.write( "(1) $\"+a+=+b+-+.2b+\"$
\n" ); document.write( "(1) $\"+a+=+.8b+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+2a+%2B+2b+=+18+\"$
\n" ); document.write( "----------------------
\n" ); document.write( "(2) $\"+a+%2B+b+=+9+\"$
\n" ); document.write( "Plug (1) into (2)
\n" ); document.write( "(2) $\"+.8b+%2B+b+=+9+\"$
\n" ); document.write( "(2) $\"+1.8b+=+9+\"$
\n" ); document.write( "(2) $\"+b+=+5+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+a+=+.8b+\"$
\n" ); document.write( "(1) $\"+a+=+.8%2A5+\"$
\n" ); document.write( "(1) $\"+a+=+4+\"$
\n" ); document.write( "The rectangle is 4 x 5
\n" ); document.write( "-----------------------
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+2a+%2B+2b+=+18+\"$
\n" ); document.write( "(2) $\"+2%2A4+%2B+2%2A5+=+18+\"$
\n" ); document.write( "(2) $\"+8+%2B+10+=+18+\"$
\n" ); document.write( "(2) $\"+18+=+18+\"$
\n" ); document.write( "OK \n" ); document.write( "

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