Working through the typographical minefield of this question, I would suggest that the perimeter of the triangular field is 5.6 km.
In ascending order (16, 16, 17, 17, 17, 18, 18) it is 17 that is in the middle.
The fraction 17/18 is the same as 17 divided by 18. 17 ÷ 18 = 0.94444 . . .
no 4,913 = 17 x 17 x 17 = 17³ 5,832 = 18 x 18 x 18 = 18³
5
35-18 = 17
17/18 - 2/3 = 17/18 - 12/18 = 5/18
18 - 17 = 1
17 out of 18 = 94.44%
18
It is 18 times 17 = 306.
18/17 = 1.05882352941176
-17 - 18 = -35