Let (P, L,, ) an absolute plane. In this thesis we study some properties of absolute planes with an axiomatic approach. Then we call "motions" a special subgroup of its automorphisms grou and characterize absolute planes in singular and ordinary Moreover, we define a binary operation + over the set of point P and we show that (P, +) is "K-loop" a special algebraic structure. We introduce the notions : halfline, angle, sum of angles, cyclic ordered rotation group and orientation of triangles. Our next aim is to define a measure for angles and rotations around a point. ecially we investigate the measure of inner angles summation of a triangle in singular and ordinary cases. Finally, after defining the "defect" function of an absolute plane we study the relation between the defect of certain ltr"