> >M# = (By-Ay)/(Bx-Ax) >Dx = (Cx+((M#^2)*Ax)-(M#*Ay)+(M#*Cy))/((M#^2)+1) >Dy = (M#*(Dx-Ax))+Ay > >PRINT Dx,Dy > >Thanks for all the help, >-Joe Lertola > > >-- Joe You have to be careful to test before computing M# that Bx<>Ax in this case the solution is evident (Dx=Ax) but the general algorithm fails. To speed up the computation, I suggest long if Ax<>BX M# = (By-Ay)/(Bx-Ax) M2#= M#*M# Dx = (Cx+(M2#*Ax)-(M#*Ay)+(M#*Cy))/(M2#+1) Dy = (M#*(Dx-Ax))+Ay xelse Dx=Ax Dy=Cy end if ######################################################## # Guy Bonnot phone: +33 - 04 72 43 79 82 # # INRA - INSA fax: +33 - 04 72 43 85 34 # # Biologie 406 internet: bonnot@... # # 20, av. A. Einstein # # 69621 Villeurbanne cedex # # France # ########################################################