Question

If two parallel lines are cut by a traversal, then alternate interior angles are and co-interior angles are

• A. equal
• B. unequal
• C. supplementary
• D. complementary

Answer 1

Answer: (A), (C)

The correct options are
A equal
C supplementary

If 'm' and 'n' are two parallel lines cut by the traversal 't', then alternate interior angles are equal and co-interior angles are supplementary.
i.e., $\angle 3+\angle 6={180}^{\circ }$ and $\angle 4+\angle 5={180}^{\circ }$
Also, $\angle 4=\angle 6$ and $\angle 5=\angle 3$