5.3.1.13 Construction of sections

condition: On the edges \( S A \) and \( S C \) of the pyramid \( S A B C \) points \( P \) and \( Q \), respectively, are given. Construct a section of the pyramid by a plane parallel to the lines \( B P \) and \( A Q \) and passing through the point \( L \) taken in the face \( A B C \)