Definition of antipodal angle: The two sides of one angle are the opposite ascending lines of the other angle, and these two angles are antipodal angles. When two straight lines intersect, there is only one common vertex, and both sides of two corners are opposite extension lines. Such two angles are called antipodal angles.

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.