Answer:
30 Yards.
Explanation:
It is given that the dimensions of the square plot is 30*30 .
So that means length and breadth of the square plot both are 30 yards.
Now According to the question he want to divide the land in half so for that he will build a fence either corresponding to length or breadth.
So building a fence means just length of that fence which will be 30 Yards.
So answer is 30 Yards.