2. The definition of "edge" is different. An angle can only be the only edge corresponding to two angles, and an edge of an angle can be any one corresponding to two angles.
3. The corner edge originates from the corner edge. The sum of triangles of a triangle is 180, so when any two angles are equal, the third triangle is equal. Therefore, angles can be used to prove that triangles are equal.
ASA (Angle and Angle) means that two angles of a triangle are equal, and two angles are also equal to two triangles.
For example: AB=AC, ∠B=∠C, verify △ Abe △ ACD.
Proof: in △ABE and △ACD {∠A=∠A, AB=AC, ∠ B = ∠ C. ∴△ABE≌△ACD(ASA).
AAS (Angular Edge) means that two angles of a triangle are equal, and the edge corresponding to the equal angle also corresponds to the congruence of two equal triangles.
Example: AB=DE, ∠A=∠E, and verification ∠ b = ∠ d.
Proof: in △ABC and △EDC, {∠A=∠E, ∠ACB=∠DCE, AB=DE. ∴△ABC≌△EDC.(AAS)
Extended data
Congruent triangles refers to two congruent triangles whose three sides and three angles are equal. Congruent triangles is one of congruences in geometry. According to congruence transformation, two congruent triangles are still congruence after translation, rotation and folding.
Generally speaking, the verification of two congruent triangles is judged by the hypotenuse and right-angled side (HL) of side (SSS), corner (SAS), corner (ASA), corner (AAS) and right-angled triangle.
The following two methods cannot be verified as congruent triangles:
AAA(Angle-Angle-Angle): triangles are equal, which can not prove congruence, but can prove similar triangles.
SSA (Edge-Edge-Angle): An angle is equal, and two edges not included in the angle are equal.
Baidu Encyclopedia-congruent triangles