usecolor -2 2 setxrange -2 3 setyrange %% echelle 100 setxunit %% position de la camera 3 10 6 SetCamPos 0 0 0 SetCamView 2 setlinejoin %% dessin de la sphere /aretescachees false def .5 setlinewidth %% epaisseur du trait .6 setgray %% niveau de gris 2 [18 36] newsphere drawsolid %% r, theta, phi /A {2 90 20} def /B {2 20 40} def /C {2 120 70} def .75 setlinewidth bleu A B C trianglespherique pointilles .5 setlinewidth continu noir %% [0 0 0 A rtp2xyz] ligne3d %% [0 0 0 B rtp2xyz] ligne3d %% [0 0 0 C rtp2xyz] ligne3d %% projections de A, B, et C sur xOy pointilles [0 0 0 A rtp2xyz projxy] ligne3d [A rtp2xyz A rtp2xyz projxy] ligne3d [0 0 0 B rtp2xyz projxy] ligne3d [B rtp2xyz B rtp2xyz projxy] ligne3d [0 0 0 C rtp2xyz projxy] ligne3d [C rtp2xyz C rtp2xyz projxy] ligne3d %% on marque les points orange A rtp2xyz point3d C rtp2xyz point3d B rtp2xyz point3d noir 0 0 0 point3d %% et on inscrit leurs noms 18 setfontsize setTimesItalic (A) A rtp2xyz uctext3d (B) B rtp2xyz cltext3d (C) C rtp2xyz urtext3d (O) 0 0 0 dltext3d