If in two then

In ∆ABC and ∆PQR.

AB/QR = BC/PR = CA/PQ

We know that if sides of one triangle are proportional to the side of the other triangle, and then their corresponding angles are also equal, so by SSS similarity, both the triangles are also similar.

So, by SSS Similarity

We have, ∆CAB = ∆PQR