The first answer is SSS criteria.
The second answer is SAS criteria.
Now the first answer comes from the fact that we have two triangles which sides are congruent with each other. This means, by the side side side therorem that they have to be congruent.
The second answer comes from the fact that we have two triangle with congruent two pairs of congruent sides and that the angle between them is congruent as well; this means, by the side angle side theorem that the triangles are congruent.