Question

Two lines in a plane are cut by a transversal. Which condition does NOT imply that the two lines are parallel?

• A. A pair of alternate interior angles are congruent
• B. A pair of co-interior angles are supplementary
• C. A pair of corresponding angles are congruent
• D. A pair of alternate exterior angles are complementary

Answer 1

The correct option is D A pair of alternate exterior angles are complementary

Referring to the above figure:

OptionA:

A pair of alternate interior angles are congruent.

Angle $B$ and $E$ are congruent.

Option B:

A pair of co-interior angles are supplementary.

Angle $B+F={180}^0$

Option C:

A pair of corresponding angles are congruent.

Angle $C$ and $E$ are congruent.

Option D:

A pair of alternate exterior angles are complementary.

Angle $A+H={90}^0$

Option A, B, C will represent the parallel lines, but option D may or may not represent it.