Question 1100698
The fence length parts are 50 + x + x and the area of the fenced region is 50x.


Amount of fence material:
{{{2x+50=250}}}
{{{x+25=125}}}
{{{x=100}}}


The breeder wants to use all of the fence material and using all of it will give the greatest area.  This means 50 yards-worth opposite side from the barn and sitting 100 yards from the barn.