//! - or a constant trihedron to have all the sections
//! in a same plane
//! 2.b) Define a ConstantBinormal Direction to keep the
-//! same angle beetween the Direction and the sections
+//! same angle between the Direction and the sections
//! along the sweep surface.
//! 2.c) Define the path by a surface and a 2dcurve,
//! the surface is used to define the trihedron's normal.
-//! It is usefull to keep a constant angle beetween
+//! It is usefull to keep a constant angle between
//! input surface and the pipe. --
//! 3) give a path and two sections. The section
//! evoluate from First to Last Section.