Question

if lines are parallel, then alternate interior angles are ____________. parallel supplementary complementary congruent

Explanation:

When two parallel lines are cut by a transversal, alternate - interior angles have the same measure. Parallel refers to lines, supplementary angles add up to 180 degrees, complementary angles add up to 90 degrees. Alternate - interior angles of parallel lines are congruent.

Answer:

D. congruent