Geometrical approach to the evaluation of multileg Feynman diagrams
  A connection between one-loop $N$-point Feynman diagrams and certain geometrical quantities in non-Euclidean geometry is discussed. A geometrical way to calculate the corresponding Feynman integrals is considered. (This paper contains a brief review of the results presented in hep-th/9709216). 
A. I. Davydychev and R. Delbourgo