%@Auteur:Thierry Joffredo\par \'Ecris un programme de construction pour la figure suivante: \begin{center} \psset{xunit=0.5cm,yunit=0.5cm,dotstyle=*,dotsize=3pt 0,linewidth=0.8pt,arrowsize=3pt 2,arrowinset=0.25} \begin{pspicture*}(-6,-6)(6,6) \rput{30}{ \pscircle(0,0){2.5} \psline(-5,0)(5,0) \psline(2.5,-6.766666666666667)(2.5,10.5) \psline(2.8,0)(2.8,0.3) \psline(2.8,0.3)(2.5,0.3) \psline(1.2,0.2)(1.3,-0.2) \psline(3.7,0.2)(3.8,-0.2) \psdots(0,0) \psdots(-5,0) \psdots(5,0) \psdots(2.5,-4.330127018922193) \psdots(2.5,4.330127018922194) \psdots(2.5,0) \psdots(-3,-4) \psline[linestyle=dashed](0,0)(-3,-4) } \rput[bl](1.8,0){$H$} \rput[bl](-0.5,4){$D$} \rput[bl](3.4,-3){$C$} \rput[bl](4.8,2){$B$} \rput[bl](-5.2,-2.8){$A$} \rput[bl](-0.2,0.4){$O$} \rput[bl](-0,-3){2.5 cm} \end{pspicture*} \end{center} {\em On utilisera le vocabulaire mathématique approprié. On fera des phrases courtes et précises.}