When parallel lines are intersected by a transversal, four pairs of angles with equal measures are formed: Corresponding Angles: These are located on the same side of the transversal and in corresponding positions relative to the parallel lines. They are congruent, meaning they have the same measure. Alternate Interior Angles: Found on opposite sides of the transversal and inside the parallel lines, these angles are congruent. Alternate Exterior Angles: These angles lie on opposite sides of the transversal but outside the parallel lines, and they are congruent. Vertical Angles: Formed when two lines intersect, vertical angles are directly opposite each other at the point of intersection and are equal in measure