ifthere is a triangle ABC is congrruence to triangle PQR and if angleB =angleQ,AB=PQ AND BC=QR and angleBand Qare 90digree so they both are congrruent by sas or rhs?

The problem you have mentioned can be done by both ways SAS and RHS.

For RHS, you need to show that hypotenuse of both the triangles are equal by assuming perpendicular as "x"  and base as "y". So, hypotenuse for both the triangles comes out to be . Hope it helps you!