AAS (Angle-Angle-Side)

AAS (Angle-Angle-Side) is a criterion used in geometry to determine if two triangles are congruent, meaning they are exactly the same shape and size. It states that if two triangles have two matching angles and the length of the side between those angles (the included side), then the triangles are congruent. Essentially, knowing two angles and the side connecting them in both triangles ensures that all their other sides and angles match perfectly. This rule helps confirm the equality of two triangles without needing to check every side and angle individually.