When two angles and the included side of one triangle are respectively equal to two angles and the included side of another triangle. This is called the [[1]] congruence of triangles.

The two triangles are congruent by ASA congruence criteria if two angles and the included side of one triangle are identical to two angles and the included side of another triangle.

Here, in $△ABC and △QRP$,

$\angle B=\angle R$

$\angle C=\angle P$

$BC=RP$

∴By ASA congruence condition for triangles, $∆ABC\cong ∆QRP$.