Hassan built a fence around a square yard. it took 500500500 feet^2 2 start superscript, 2, end superscript of lumber to build the fence. the fence is 555 feet tall. what is the area of the yard inside the fence?

The length of the fence is its area divided by its height:
  fence length = (500 ft²)/(5 ft) = 100 ft

Since the yard is square, it has 4 equal-length sides. Each side of the yard is bounded by 1/4 of the total fence length, or 25 ft.

The area of the yard is the square of its side length, (25 ft)² = 625 ft².

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