size(10cm,0);
import base_pi; 

defaultpen(fontsize(12pt)+blue); // Stylo par défaut
pen p=fontsize(8pt)+black;  // Un stylo particulier 

draw(unitcircle);
path axecos = (-1,0)--(1.5,0),
     axesin = (0,-1)--(0,1.5),
     axetan = (1,-1.2)--(1,1.9);
draw(axecos,Arrow());
draw(axesin,Arrow());
draw(axetan,Arrow());
pair t30 = extension((0,0),dir(30),(1,0),(1,1)),
     t45 = extension((0,0),dir(45),(1,0),(1,1)),
     t60 = extension((0,0),dir(60),(1,0),(1,1));
draw(dir(30)--t30^^dir(45)--t45^^dir(60)--t60,dashed);

int k=24;
real a=360/k;
for (int i=-11; i<k-11; ++i)
{
  if (i==0 || (pgcd(i,2)!=1 || pgcd(i,3)==3)) {
    pair pC=dir((i)*a);
    label(texfrac(2*(i),k,factor="\pi"),pC,align=pC,Fill(white));
    draw((0,0)--pC);
  }
}
for (int j=30; j<=60; j+=15)
{
  draw(dir(j)--dir(180-j)--dir(j-180)--dir(-j)--cycle,dashed);
}

label("$\frac{1}{2}$",(.5,0),align=S,p,Fill(white));
label("$-\frac{1}{2}$",(-.5,0),align=S,p,Fill(white));
label("$\frac{1}{2}$",(0,.5),align=E,p,Fill(white));
label("$-\frac{1}{2}$",(0,-.5),align=E,p,Fill(white));
label("$\frac{\sqrt2}{2}$",(.707,0),align=N,p,Fill(white));
label("$-\frac{\sqrt2}{2}$",(-.707,0),align=N,p,Fill(white));
label("$\frac{\sqrt2}{2}$",(0,.707),align=W,p,Fill(white));
label("$-\frac{\sqrt2}{2}$",(0,-.707),align=W,p,Fill(white));
label("$\frac{\sqrt3}{2}$",(.866,0),align=S,p,Fill(white));
label("$-\frac{\sqrt3}{2}$",(-.866,0),align=S,p,Fill(white));
label("$\frac{\sqrt3}{2}$",(0,.866),align=E,p,Fill(white));
label("$-\frac{\sqrt3}{2}$",(0,-.866),align=E,p,Fill(white));

label("\begin{minipage}{1.5cm}
           \centering axe des\\ cosinus
        \end{minipage}",(1.4,0),align=N,p,Fill(white));
label("\begin{minipage}{1.3cm}
           \centering axe des\\ sinus
       \end{minipage}",(0,1.4),align=W,p,Fill(white));
label("\begin{minipage}{1.4cm}
           \centering axe des\\ tangentes
       \end{minipage}",(1,1.9),align=W,p,Fill(white));
label("$\sqrt3$",(1,1.73),align=E,p,Fill(white));
label("$1$",(1,1),align=E,p,Fill(white));