Alex drew two line segments ab and cd that are parallel to each other. what must be true if the line joining ac is perpendicular to cd?
(a) line segments ab and cd are of equal lengths.
(b) line segments ab, bc, and cd are of equal lengths.
(c) ac is the shortest distance between line segments ab and cd.
(d) the lengths of line segments ac and ab are less than the length of line segment ab.