PQR is a triangle. The area of the square of side QR is equal to that of a rectangle whose length is PR and breadth is RS where S is a point on PR such that QS is perpendicular to PR. What can be concluded regarding the angles of triangle PQR?

PQR is a triangle. The area of the square of side QR is equal to that of a rectangle whose length is PR and breadth is RS where S is a point on PR such that QS is perpendicular to PR. What can be concluded regarding the angles of triangle PQR?