SSS Congruency

Q. In the given figure, if AB = AC and D is the midpoint of BC, then which of the following is true ?

1. $△ADB\cong △ADC$ by RHS postulate
2. $△ADB\cong △ADC$ by SSS postulate
3. AD bisects $\angle BAC$
4. If $\angle BAC={80}^{\circ },$ then $\angle ABD={80}^{\circ }$