A statement that switches the hypothesis and conclusion and negates both

Contrapositive – the statement formed by negating both the hypothesis and conclusion of the converse of a conditional statement.

Converse – the statement formed by exchanging the hypothesis and conclusion of a conditional statement. Counterexample – an example used to show that a given statement is not always true.

Skew lines(segments) are lines(segments) in 3 dimensions that do not intersect the given segment and are not parallel to it.  ae, bf, eg, and fh are your skew segments.  i hope that : )