∠9 and ∠10 are angles formed by parallel lines cut by a transversal. They are also said to be same-side interior angles. Which of the following best describes the relation between the two angles? *
A. They are supplementary angles.
B. None of the above.
C. They are complementary angles.
D. They are complements of each other.
According to the same side interior angle theorem, "If a transversal intersects two parallel lines, each pair of same-side interior angles are supplementary (their sum is 180°)."
