Question 465309
It is possible to put poles 9 ft, 19 ft, 29 ft, ..., 139 ft from an endpoint, implying you will need 14 poles. Or, you could put the first pole close to the starting point, e.g. 1 ft, 11 ft, 21 ft, ..., 141 ft, calling for 15 poles. In either case you will need at least 14 poles.