5.3.1.14 Construction of sections

condition: On the edges \( A C, B C \) and \( C C_{1} \) of the prism \( A B C A_{1} B_{1} C_{1} \) the points \( Q, R \) and \( S \) are given, respectively. Construct a section of the prism by a plane parallel to the plane \( Q R S \) and passing through the point \( P \) defined on the edge \( B B_{1} \).