Yes, the three given lengths will form a triangle.Three lengths can make a triangle if, and only if, the sum ofthe two shorter lengths is greater than the longest length.The two shorter lengths are 56 ft and 16 ft with a sum of 56 ft+ 16 ft = 72 ft72 ft is greater than 65 ft so 56 ft, 65 ft and 16 ft will makea triangle.