Lines e and f are parallel since their alternate exterior angles 75 ad 75 are congruent.
Step-by-step explanation:
Parallel lines mean that angle relationships exits where specific angles are congruent to each other. 75 and 75 are in the position of alternate exterior angles for lines e and f. Since they are congruent, these lines must be parallel. However, a and b have same side exterior angles which must add to 180. 75 + 115 does not equal 180. It equals 190. Therefore a and b cannot be parallel.
