1. The problem asks to identify the postulate that makes the two triangles congruent. 2. The triangles share two pairs of congruent sides: AC \cong AD (given by tick marks). 3. The angle at vertex A is congruent in both triangles (given by the arc). 4. The side AB is common to both triangles, so AB \cong AB by the Reflexive Property. 5. Therefore, the triangles have two sides and the included angle congruent: side AC \cong side AD, angle at A congruent, and side AB common. 6. This matches the SAS (Side-Angle-Side) postulate for triangle congruence. 7. Hence, the triangles are congruent by the SAS postulate.