I'm guessing that you have a quadrilateral PQRS with a point T somewhere inside of it. But without knowing what sort of quadrilateral, if it is indeed something other than a general quadrilateral, and what the relationship point T has with the vertices, there is no way to solve this. Also, when you re-post this (and I highly recommend you re-post to the site rather than writing directly to me -- I may not have time to get to you), make sure you specify the order of the vertices.
