Answer
The sum of the angles of the triangle is $180^o.$ Hence if $2$ angles are equal then the third one will be equal too. Hence if a corresponding side and all angles are equal, then they are congruent by the A-S-A theorem (Given two adjacent angles $\alpha$ and $\beta$ and the side between them c uniquely determines a triangle ).
Work Step by Step
The sum of the angles of the triangle is $180^o.$ Hence if $2$ angles are equal then the third one will be equal too. Hence if a corresponding side and all angles are equal, then they are congruent by the A-S-A theorem (Given two adjacent angles $\alpha$ and $\beta$ and the side between them c uniquely determines a triangle ).
