Answer:
ii. Yes, a solution always exists.
iii. There is only one congruent solution to the problem.
Explanation:
Two or more lines are said to be congruent is they have the same length. These lines could be at certain angles to each other, which can be constructed to produce a triangle.
Given line segments, constructing a triangle with sides congruent to the line would produce only one triangle.
See the attachment for an example of the construction.