Question

Which postulate can be used to prove that two triangles are congruent

Answer 1

Side-Side-Side Theorem, Side-Angle-Side, Angle-Angle-Side, Angle-Side-Angle, and Hypotenuse-Leg for right triangles. 

For example, for Side-Side-Side, if you prove all 3 sides of the triangle are congruent, then the triangle is congruent.