Geodesic
The Harmonic Analysis of Polygons and Napoleon's Theorem
Journal for geometry and graphics, Tome 5 (2001) no. 1, pp. 013-022 
P. Pech. The Harmonic Analysis of Polygons and Napoleon's Theorem. Journal for geometry and graphics, Tome 5 (2001) no. 1, pp. 013-022. http://geodesic.mathdoc.fr/item/JGG_2001_5_1_a1/
@article{JGG_2001_5_1_a1,
     author = {P. Pech},
     title = {The {Harmonic} {Analysis} of {Polygons} and {Napoleon's} {Theorem}},
     journal = {Journal for geometry and graphics},
     pages = {013--022},
     year = {2001},
     volume = {5},
     number = {1},
     url = {http://geodesic.mathdoc.fr/item/JGG_2001_5_1_a1/}
}
TY  - JOUR
AU  - P. Pech
TI  - The Harmonic Analysis of Polygons and Napoleon's Theorem
JO  - Journal for geometry and graphics
PY  - 2001
SP  - 013
EP  - 022
VL  - 5
IS  - 1
UR  - http://geodesic.mathdoc.fr/item/JGG_2001_5_1_a1/
ID  - JGG_2001_5_1_a1
ER  - 
%0 Journal Article
%A P. Pech
%T The Harmonic Analysis of Polygons and Napoleon's Theorem
%J Journal for geometry and graphics
%D 2001
%P 013-022
%V 5
%N 1
%U http://geodesic.mathdoc.fr/item/JGG_2001_5_1_a1/
%F JGG_2001_5_1_a1

Voir la notice de l'article provenant de la source Heldermann Verlag

Plane closed polygons are harmonically analysed, i.e., they are expressed in the form of the sum of fundamental k-regular polygons. From this point of view Napoleon's theorem and its generalization, the so-called theorem of Petr, are studied. By means of Petr's theorem the fundamental polygons of an arbitrary polygon have been found geometrically.