Question 1191127
Draw this out. The horse has 3/4 of the area of a circle with radius of 18 m. That part is relatively straightforward.  The area is π*18^2*(3/4)=243 pi m^2.
But if the horse stays along the fence and goes down the next side, it is like being on an 8 m tether for 1/4 of a circle. There are 2 ways this can happen. The area of a circle with an 8 meter radius is 64π m^2, and there are 2 (1/4) circles, so that is like a 1/2 circle, or 32π m^2

The total area is 275 π m^2.