%@AUTEUR:Guillaume Connan
prologues:=2;

verbatimtex
%&latex
\documentclass{article}
\begin{document}
etex

input courbes;
input geo;

color vert_e, turquoise, orange, vert_fonce, rose, vert_mer, bleu_ciel, or, rouge_v,bleu_m,bleu,bleu_f;
vert_e:=(0,0.790002,0.340007);
turquoise:=(0.250999,0.878399,0.815699);
orange:=(0.589999,0.269997,0.080004);
vert_fonce:=(0,1.4*0.392193,0);
rose:=(1.0, 0.752907, 0.796106);
bleu_ciel:=(1.2*0.529405,1.2*0.807794,1);%.2*0.921598);
or:=(1,0.843104,0);
rouge_v:=(0.829997,0.099994,0.119999);
bleu_m:=(0.7*0.529405,0.7*0.807794,0.7);%*0.921598);
bleu_f:=(0.211762,0.3231176,0.3686392);
bleu:=(0.529405,0.807794,1);

%  ROTATIONS

beginfig(1);
  
  pair b,bb,bbb;
  b=(7cm,0);bb=b rotated 15;bbb=bb rotated 30; 
  
  drawarrow(0,0)--(4cm,0)withpen pencircle scaled 1.3bp;
  drawarrow(0,0)--bb;
  drawarrow(0,0)--bbb withcolor bleu_m;

  label.rt(btex $M$ etex,bb);
  label.ulft(btex $M'$ etex, bbb) withcolor bleu_m;
  label.ulft(btex $C$ etex, origin);
  label.bot(btex $\overrightarrow{u}$ etex, (2cm,0));

%Tracé arc de cercle

  draw bb{dir(90+angle (bb))}..{dir(90+angle (bbb))}bbb dashed evenly withcolor bleu_m ;

%Tracé de la flèche arrondie
  pair C; % point de départ de la flèche
  pair D; % point d'arrivée de la flèche
  
  C=1/3(origin+bb);
  D=C rotated 30;
  
  drawarrow C{dir(90+angle (C))}..{dir(90+angle (D))}D withcolor bleu_m;
  
  label.urt(btex $\alpha$ etex,C rotated 15) withcolor bleu_m;

  pair CC; % point de départ de la flèche
  pair DD; % point d'arrivée de la flèche
  
  CC=1/4(origin+b);
  DD=CC rotated 15;
  
  drawarrow CC{dir(90+angle (CC))}..{dir(90+angle (DD))}DD;
  
  label.urt(btex $\theta$ etex,CC rotated 7);

endfig;
end