Reply to comment
The first correct solution we received for Puzzle No 8 - The Gobbling Goat was this one from V. Shashidhar.
You can see the more detailed PASS Maths solution for a step-by-step explanation of how to tackle the problem.
The answer to the question is 115.8 metres.
It comes as a root to the equation
where metres and is the length of the rope used to tie the goat.
The derivation is as follows (see figure):
This implies equation (1).