Step-by-step explanation:
You want to show AL≅AM in the given figure.
Statement . . . . Reason
1. AB≅AC . . . . given
2. ∠1≅∠3 . . . . given
3. ∆ABC is isosceles . . . . definition of isosceles triangle
4. ∠B≅∠C . . . . base angles are congruent in an isosceles triangle
5. ΔLBA≅ΔMCA . . . . ASA congruence postulate
6. AL≅AM . . . . CPCTC