// import geometry_dev; // extension devenue l'extension geometry officielle
import geometry;        // le 12/05/09, dans la version 1.71 d'asymptote. :-))

size(7.5cm,0);
show(currentcoordsys);
circle C=circle((0,0),1);
draw(C, linewidth(bp));
point pA=curpoint(C,pi/3),
      pB=curpoint(C,-pi/6),
      pC=curpoint(C,3pi/4),
      pD=curpoint(C,-2pi/3),
      pE=curpoint(C,pi);
pen p1=5bp+blue, p2=dashed;
dot(pA,p1); draw(pA--projection(Ox)*pA,p2);
dot(pB,p1); draw(pB--projection(Oy)*pB,p2);
dot(pC,p1); draw(pC--(0,0),p2);
dot(pD,p1); draw(pD--projection(Ox)*pD,p2);
dot(pE,p1); 

markangle(Oy,Ox,StickIntervalMarker(2,2,true));

draw((0,0)--(1,0),invisible,StickIntervalMarker());
draw((0,0)--(0,1),invisible,StickIntervalMarker());
draw((0,0)--(-1,0),invisible,StickIntervalMarker());

addMargins(.5cm,.5cm);