Thanks for the replies but I must have worded the question wrong. The anchor point of the leash is non moving, it must stay still. The goat however can move on the circumference of the invading circle as illustrated in my attachment.
I have a circular paddock with AREA: 1 unit^2. If I have a goat with a leash tied to the outer fence (circumference of paddock), how long must the leash, L, be to only allow the goat to eat half the grass in the paddock?
-sorry if my wording confuses anyone (im a left brainer)
Yeah that's how it works. If physics was your lowest mark but you were doing only 11 units, they would count the top 10 (i.e. incl. Ext 1 and half of your physics result.