A 45 degree angle is 1/8 of a circle, so keep that in mind for later. You're looking for the circumference of that 1/8 fence, so you have to use the formula, circumference/diameter=pi. Now, the problem gives you half the diameter, a.k.a the radius, so double it to get 44 ft. then, you multiply that by 3.14 (pi) to get 138.16. Now take the 1/8, from before, of the circumfrence and you get your final answer, 17.27 ft!
