Question 1102122
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The other tutor didn't read the problem correctly....<br>
The circular grass yard has a circumference of 520 feet.
The radius of the yard is {{{520/(2*pi) = 260/pi}}} feet, or about 82.76 feet.
The area of the yard is (pi)*r^2: {{{(pi)*(260/pi)^2}}}, about 21517.75 square feet.<br>
The square rock garden in the middle has an area of 90^2=8100 square feet.<br>
The area of grass in square feet is {{{21517.75-8100=13417.75}}}.