A triangle is bounded by three sides, thus it has three angle. When two triangles are compared, the length of sides and angles could be similar or not. Thus, the triangle may be congruent or not congruent.
The relationship between congruent triangles can be expressed as regards to their sides, angles, or both.
From the given question, when the three angles of two given triangles are the same, then the two triangles are congruent. This relationship can be expressed as Angle-Angle-Angle.
Also, when two triangles have two equal sides and an included angle to be equal (i.e Side-Angle-Side), then they are congruent.