We can use the properties of parallel lines and transversals to determine the measures of the angles.
From the given information, we know that lines e and f are parallel, and the angles 9 and 80° form a linear pair, which means that angle 9 measures 180° - 80° = 100°.
Similarly, angle 5 and 55° form a linear pair, so angle 5 measures 180° - 55° = 125°.
Using the alternate interior angles property, we know that angles 3 and 8 are congruent, and both are equal to angle 5 - angle 4 = 125° - 80° = 45°. Therefore, option (ii) is incorrect.
Using the corresponding angles property, we know that angles 12 and 6 are congruent, and both are equal to angle 9 + angle 80° = 100° + 80° = 180°. Therefore, option (iv) is correct.
Using the vertical angles property, we know that angles 14 and 2 are congruent, and both are equal to angle 80°. Therefore, option (v) is correct.
Therefore, the correct options are (i) mangle2 = 125°, (iv) mangle12 = 100°, and (v) mangle14 = 100°.