document.write( "Question 1182220: The area of the shaded region represents one-third of the total, What is the
\n" ); document.write( "size of the radii such that this is possible? \r
\n" ); document.write( "\n" ); document.write( "The radius of the whole circle is 12cm while the shaded region is a ring in
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Algebra.Com's Answer #812271 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Since the green area is 1/3 of the area of the outer circle, the area of the\r\n" );
document.write( "inner circle is 2/3 of the area of the outer circle.\r\n" );
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document.write( "Using the area of a circle formula \"A=pi%2Ar%5E2\",\r\n" );
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document.write( "\"pi%2Ar%5E2=expr%282%2F3%29pi%2A12%5E2\"\r\n" );
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document.write( "\"cross%28pi%29%2Ar%5E2=expr%282%2F3%29cross%28pi%29%2A12%5E2\"\r\n" );
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document.write( "\"r%5E2=expr%282%2F3%2912%5E2\"\r\n" );
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document.write( "\"r%5E2=expr%282%2F3%29%28144%29\"\r\n" );
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document.write( "\"r%5E2=96\"\r\n" );
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document.write( "\"r=sqrt%2896%29\"\r\n" );
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document.write( "\"r=sqrt%2816%2A6%29\"\r\n" );
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document.write( "\"r=4sqrt%286%29\"\r\n" );
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document.write( "So the radius of the inner circle must be 4√6 or about 9.8 cm.\r\n" );
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document.write( "Edwin
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