Five different sets of measurements for a triangle are given below. For each set, state whether a unique triangle can always be constructed, sometimes be constructed, or never be constructed. In each case give a clear justification referring to an appropriate congruence condition or to the lack thereof.
(a) Two sides and the included angle
(b) Two angles and the included side
(c) Three sides
(d) Two sides and a non-included angle
(e) The hypotenuse and one leg of a right-angled triangle