Definition of complementary angle: the sum of two angles is 180 degrees. That is, the two angles are complementary.
Definition of congruent angle: Two angles on the same side of the tangent are called congruent angles.
Definition of ipsilateral internal angle: Two angles on the same side of a tangent are called ipsilateral internal angles in two tangents.
Definition of internal dislocation angle: The two angles inside and on the other side of two tangents are called internal dislocation angles.