(সম্পূর্ণ) কোণ-বাহু-কোণ সর্বসমতা: সকল ট্রান্সফরমেশন ব্যবহার করে

This is pretty much the same as AAS Congruence. The only difference is that in ASA, the side is enclosed by the two angles.

Consider $\triangle ABC$ and $\triangle DEF$. For the two to be congruent, they must be similar with a scale factor of $1$. If we know that two corresponding angles are equal, then by AA similarity, $\triangle ABC\sim\triangle DEF$. From similarity,

$$\frac{AB}{DE}=\frac{BC}{EF}=\frac{CA}{FD}$$

But, if two corresponding lengths are equal, say $AB=DE$,

$$1=\frac{AB}{DE}=\frac{BC}{EF}=\frac{CA}{FD}$$

which means all corresponding sides are equal! Therefore, the triangles are congruent.

ASA Congruence states that in two triangles if two pairs of corresponding angles are equal and one pair of corresponding sides is equal, then the two triangles are congruent.

Remark: If $\angle A=\angle D$, $\angle B=\angle E$, and $AB=DE$, $\triangle ABC\cong\triangle DEF$. Why does this fail if $\angle A=\angle D$, $\angle B=\angle E$, and $AB=EF$?

Answer: because the sides are not corresponding!