An acre is a surface measure, used in agriculture in several countries.
According to the country and the time, it is equivalent to several surfaces.
We will use the following conversion:
1 acre = 43560 feet ^ 2
Thus:
40 acre = 1,742,400 feet ^ 2
The area of the rectangle is:
1,742,400 = (1,200) * (x)
Clearing the other dimension we have:
x = (1742400) / (1200)
x = 1452 feet
Answer:
He needs 1452 feet of fence.
