document.write( "Question 894054: What is the length of the diameter of a circle with an area of 9pi square units? \n" ); document.write( "
Algebra.Com's Answer #541707 by MathTherapy(10552)\"\" \"About 
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\n" ); document.write( "What is the length of the diameter of a circle with an area of 9pi square units?
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\n" ); document.write( "\"pi+%2A+r%5E2+=+area_of_circle\"
\n" ); document.write( "Let diameter be D
\n" ); document.write( "Since area = \"9%28pi%29\", and radius = \"D%2F2\", then: \"pi+%2A+r%5E2+=+area_of_circle\" becomes: \"pi+%2A+%28D%2F2%29%5E2+=+9+%2A+pi\"
\n" ); document.write( "\"pi+%2A+%28D%5E2%2F4%29+=+9+%2A+pi\"
\n" ); document.write( "\"%28pi+%2A+D%5E2%29%2F4+=+9+%2A+pi\"
\n" ); document.write( "\"pi+%2A+D%5E2+=+36+%2A+pi\" ------ Cross-multiplying
\n" ); document.write( "\"pi%2A%28D%5E2%29+=+pi+%2A+%2836%29\" ------ Factoring out GCF, \"pi\"
\n" ); document.write( "\"D%5E2+=+36\"
\n" ); document.write( "D, or diameter = \"sqrt%2836%29\", or \"highlight_green%286%29\" \n" ); document.write( "
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