Is the following definition of perpendicular reversible? if yes, write it as a true biconditional. two lines that intersect at right angles are perpendicular. a. the statement is not reversible. b. yes; if two lines intersect at right angles, then they are perpendicular. c. yes; if two lines are perpendicular, then they intersect at right angles. d. yes; two lines intersect at right angles if (and only if) they are perpendicular.