document.write( "Question 612490: how many cubic yards of cement are needed to make a concrete walkway around a rectangle garden which is 20 feet by 35 feet, if the walkway is to be 3 feet wide and 4 inches thick? \n" ); document.write( "

Algebra.Com's Answer #385517 by Edwin McCravy(20055) $\"\"$ $\"About$

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document.write( "We'll first find the area of the top of the walkway in square feet\r\n" );
document.write( "and then multiply that area by the the thickness of 4 inches, or\r\n" );
document.write( " ft to find the volume.  We'll find it in cubic feet and \r\n" );
document.write( "then convert to cubic yards.\r\n" );
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document.write( "The inner rectangle is 20ft×35ft, so it has an area of 700 sq.ft.  \r\n" );
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document.write( "The larger rectangle is 6 feet more on each dimension (since the\r\n" );
document.write( "walkway is 3 feet more on each side of each dimension), so it is\r\n" );
document.write( "26ft×41ft.  It has an area of 1066 sq. ft. This is the picture of \r\n" );
document.write( "the top of the walk. \r\n" );
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document.write( "To find the area of the top of the walkway, we subtract the area\r\n" );
document.write( "of the inner rectangle from the area of the larger rectangle.\r\n" );
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document.write( "Area of top of walkway = 1066 sq ft - 700 sq ft = 366 sq ft.\r\n" );
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document.write( "Since it is 4 inches thick, which is  ft, we find the \r\n" );
document.write( "volume by multiplying the area of the top of the walkway by the\r\n" );
document.write( "thickness and get 366× = 122 cubic feet.\r\n" );
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document.write( "Finally we must convert cubic feet to cubic yards.  There are 27 cubic\r\n" );
document.write( "feet in 1 cubic yard, so we divide 122 by 27 and get 4.518518519\r\n" );
document.write( "cubic yards.\r\n" );
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document.write( "Edwin

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