Question 965830
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Cannot say exactly, as I cannot see the diagram shown, but in general:
Perimeter of the rectangle -diameter of semicircle +  half circumference for semicircle
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Perimeter of rectangle=2(Length+Width)=2(31ft+23ft)=2(54ft)=108 feet
The length of 1/2 circumference of circle=1/2(pi)(diameter)
Since the diameter of the semicircle is taken away from the perimeter of th rectangle, over all we have:
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Fence needed=108 feet - diameter of semicircle + 1/2(pi)(diameter of semicircle)