Let l be the length of the farm and b be the breadth.
Then, according to the question,
l=10+2b
Let x be the side of the pond, then,
x=13b
The area of the square pond is,
A=(13b)2
A=19b2
The area of the farm is,
A=l×b
A=(10+2b)(b)
A=10b+2b2
According to the question,
Areaofthefarm=20(areaofthepond)
10b+2b2=20(19b2)
90b+18b2=20b2
2b2−90b=0
2b(b−45)=0
2b=0
b=0
Or,
b=45
Since the breadth cannot be 0, so the breadth of the farm is 45m. Then, the length is,
l=10+2(45)
l=100m
Therefore, the length of the farm is 100m and the breadth of the farm is 45m.