Which biconditional is NOT a good definition?

A) Two line segments are congruent if and only if they have same length.

B)Three points are collinear if and only if they lie on the same line.

C) A whole number is even if and only if it is divisible by 2.

D) Two lines are parallel if and only if they do not intersect.

Question

Which biconditional is NOT a good definition?


A) Two line segments are congruent if and only if they have same length.

B)Three points are collinear if and only if they lie on the same line.

C) A whole number is even if and only if it is divisible by 2.

D) Two lines are parallel if and only if they do not intersect.

anonymous · Answer

@terrance20 or @skullpatrol 
can one of you guys help plz?