Interior angles on the alternate sides of the transversal are equal if the lines are parallel. These are called?

• A. Co-interior Angles
• B. Exterior Angles
• C. Alternative Angles
• D. Corresponding Angles

Answer: (C)

Alternate interior angles are the interior angles on opposite sides of a transversal when it cuts two parallel lines, and they are equal. That specific description matches the term in the options: Alternative Angles. The other terms describe different angle relationships: co-interior angles are interior on the same side of the transversal and sum to 180 degrees; exterior angles lie outside the region between the lines; corresponding angles are in matching positions and are equal when the lines are parallel, but they are not the interior ones on opposite sides. So the best fit for the described pair is Alternative Angles. A handy picture is the Z-shaped arrangement formed inside the parallel lines, which visually shows their equality.