Advanced Math/Area


900 rails are required to fence an acre.  A square field contains as many acres as rails in the fence enclosing it.  Calculate area of the square field.  

The problem does not state if the acre is square or rectangular, or length of rails.

I know this problem is similar to the fence - area problem posted previously.


"900 rails are required to fence an acre"
I'll assume this one-acre field is square, so each side of the fence contains 900/4 = 225 rails.

"Another square field has as many acres as rails"
Suppose the field is x acres width and x acres long, then it contains x acres and there are x rails in the fence.

Find the number of rails on one side of the field.
x acres 225 rails/acre = 225x rails
Total number of rails in the fence = 4225x = 900x

Solve for x:
x = 900x
x = 900

Area of the field is 900 = 810,000 acres.

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