4a.
Inverse: If two segments are not of same length, then they are not congruent. TRUE
Converse: If two segments are congruent, they have the same length. TRUE
Contrapositive: If two segments are not congruent, then they do not have the same length. TRUE
4b.
Inv: if x not= 3, then |x| not= 3. FALSE. Counterexample: x=-3
Conv.: if |x|=3 then x=3. FALSE. Ex: x=-3
Contr: if |x| not=3 then x not= 3. TRUE
