Mathematical geometry concepts and images: What are equal angles and what are congruent angles? (It is best to have pictures)

Congruent angles - equal angles,

Congruent angles - the same angle.

Above: ∠1=∠2, ∠1 and ∠ are equal angles,

In the figure below, ∠1 and ∠2 are mutually supplementary,

∠1 and ∠3 are mutually supplementary,

Then ∠2 and ∠3 That is: the supplementary angle of an angle (∠1).