input geometriesyr16; typerepre:="persp"; figureespace(-5u,-5u,5u,5u); Initialisation(10,0,10,35); trace cercles((0,0,0),(0,0,2),(0,0,0),(0,1,0),(0,0,1)); path CL; color M,M'; color Cent; M=(0,2*cosd(-130),2*sind(-130)); Cent=ProjectionsurPlan(M,(0,0,0),(0,2*cosd(120),2*sind(120)),(1,0,0)); M'=(-1,greenpart(Cent),bluepart(Cent)); path Sect; Sect=cercles(Cent,M,Cent,M,M'); remplis Sect withcolor 1.1*gris; trace subpath(0,length Sect/2) of Sect dashed evenly; trace subpath(length Sect/2,length Sect) of Sect; CL=cercles((0,0,0),(0,2,0),(0,0,0),(0,1,0),(1,0,0)); trace subpath(0,length CL/2) of CL; trace subpath(length CL/2,length CL) of CL dashed evenly; trace polygone(Cent,M,(0,0,0)) dashed evenly; trace codeperp((0,0,0),Cent,M,5); marque_p:="plein"; pointe(M,(0,0,0),Cent); marque_p:="non"; label.top(btex $O$ etex,Projette((0,0,0))); label.bot(btex $I$ etex,Projette(Cent)); label.llft(btex $M$ etex,Projette(M)); finespace; figureespace(-5u,-5u,5u,5u); Initialisation(10,0,10,35); color M,M',Cent; path CL,CF,Sect,plansec; CL=cercles((0,0,0),(0,2,0),(0,0,0),(0,1,0),(1,0,0)); CF=cercles((0,0,0),(0,0,2),(0,0,0),(0,1,0),(0,0,1)); M=(0,2*cosd(-130),2*sind(-130)); Cent=ProjectionsurPlan(M,(0,0,0),(0,2*cosd(120),2*sind(120)),(1,0,0)); M'=(-1,greenpart(Cent),bluepart(Cent)); Sect=cercles(Cent,M,Cent,M,M'); plansec=polygone(M'+2*(M'-Cent)+1.5*(M-Cent),M+3*(Cent-M')+0.5*(M-Cent), Cent+1.5*(Cent-M)+3*(Cent-M'),M'+2*(M'-Cent)+1.5*(Cent-M)); %partie supérieure trace plansec cutafter CF; trace segment(M'+2*(M'-Cent)+1.5*(M-Cent),M'+2*(M'-Cent)+1.5*(Cent-M)) cutafter reverse(CF); trace plansec cutbefore CF dashed evenly; trace CF cutbefore demidroite(Cent,symetrie(M,Cent)) cutafter segment(M,M); remplis Sect withcolor 1.1*gris; trace subpath(0,length Sect/2) of Sect dashed evenly; trace subpath(length Sect/2,length Sect) of Sect; trace polygone(Cent,M,(0,0,0)) dashed evenly; trace codeperp((0,0,0),Cent,M,5); marque_p:="plein"; pointe(M,(0,0,0),Cent,M'); marque_p:="non"; label.top(btex $O$ etex,Projette((0,0,0))); label.bot(btex $I$ etex,Projette(Cent)); label.llft(btex $M$ etex,Projette(M)); %partie inférieure picture sectiondecalee; sectiondecalee=image( trace CF cutafter demidroite(Cent,symetrie(M,Cent)); trace CF cutbefore segment(M,M); trace Sect; trace hachurage(Sect,60,0.2,0); ); trace sectiondecalee shifted(3*(Projette(Cent)-Projette((0,0,0)))); drawarrow segment(M+2*Cent,Cent+3*Cent); label.lft(btex Section etex,Projette(M+2*Cent)); finespace; end