document.write( "Question 1087465: a circular plot 36 feet in diameter is paved by straight concrete path 9 feet wide . one edge of path passes through the center of the plot determine the number of square feet in the remaining sand area \n" ); document.write( "

Algebra.Com's Answer #701773 by ikleyn(52781) $\"\"$ $\"About$

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document.write( "Let O be the center of the circle.\r\n" );
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document.write( "Let AB be the diameter of the circle which is one edge of the path.\r\n" );
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document.write( "Notice that the radius of the circle is  = 18 feet.\r\n" );
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document.write( "Clearly, the line AB goes through the center O.\r\n" );
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document.write( "Let CD be the other edge of the path, parallel to AB.\r\n" );
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document.write( "Draw the radius OD and notice that sin(BOD) =  = .\r\n" );
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document.write( "Hence, the angle BOD is 30°, and the angle DOC is 180° - 2*30° = 120°.\r\n" );
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document.write( "This problem is intended for an advanced student,\r\n" );
document.write( "and the HINT that I gave in previous lines is enough for such a student to complete the solution on his/her own.\r\n" );
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