1. **State the problem:** Prove that two triangles are congruent if two sides and the included angle are the same. 2. **Recall the SAS Congruence Theorem:** If two sides and the included angle of one triangle are equal to two sides and the included angle of another triangle, then the triangles are congruent. 3. **Set up the triangles:** Consider triangles $\triangle ABC$ and $\triangle DEF$ such that: - $AB = DE$ - $AC = DF$ - $\angle BAC = \angle EDF$ 4. **Explain the included angle:** The angle $\angle BAC$ is between sides $AB$ and $AC$, and similarly $\angle EDF$ is between sides $DE$ and $DF$. 5. **Apply the SAS theorem:** Since two sides and the included angle are equal, by the SAS theorem, $\triangle ABC \cong \triangle DEF$. 6. **Conclusion:** Therefore, the two triangles are congruent, meaning all corresponding sides and angles are equal.