Corresponding angles are angles that occupy the same relative position at each intersection when two parallel lines are intersected by a third line, called a transversal. According to the definition of corresponding angles, two angles are corresponding angles if they meet the following criteria:
- They lie at different corners.
- They lie on the same (corresponding) side of the transversal.
- One angle is an interior angle, and the other is an exterior angle.
The corresponding angle postulate states that corresponding angles are congruent if the transversal intersects two parallel lines. In other words, if a transversal intersects two parallel lines, the corresponding angles will always be equal. Corresponding angles are used in geometry to test for congruence and similarity by comparing corresponding sides and corresponding angles of polygons.
