1, SSS (side by side), when three sides of a triangle are equal, then the two triangles are congruent triangles.
2, SAS (Angle), two sides and the triangle with equal included angle is congruent triangles.
3.ASA (Angle and Angle), where two angles and their sides correspond to congruences of equal triangles.
4.AAS (corner edge), in which the opposite sides of two corners and one corner correspond to equal triangular congruences.
5, RHS (right angle, hypotenuse, edge), in a pair of right-angled triangles, the hypotenuse is equal to the other right-angled edge.
Congruent triangles nature:
1 and the angle corresponding to congruent triangles are equal.
2. The corresponding sides of congruent triangles are equal.
3. Vertices that can completely coincide are called corresponding vertices.
4. The heights of the corresponding sides of congruent triangles are equal.
5. The bisectors of the corresponding angles of congruent triangles are equal.
6. The median lines of the corresponding sides of congruent triangles are equal.
7. congruent triangles is equal in area and circumference.
8. The trigonometric functions of congruent triangles corresponding angles are equal.