RETOUR AU SOMMAIRE GÉNÉRAL - RETOUR AU SOMMAIRE DES FIGURES

FIGURES DANS L'ESPACE EN 2NDE







Le préambule



Le préambule sera toujours :
input couleur;

verbatimtex
%&latex
\documentclass{article}
\usepackage[upright]{fourier}
\usepackage{preambule}
\begin{document}
etex
avec mon fichier preambule.sty où se trouvent quelques rares macros utilisées ici, comme \ve{} par exemple pour les vecteurs. Il faut bien sûr avoir sous la main une version de couleur Ces figures ont été créées par David NIVAUD. Je les ai juste un peu améliorées esthétiquement et en ai créées d'autres sur le même modèle.







Les figures



Le code est situé en-dessous de sa figure !
Figure fig2c_espace1: figfig2c_espace1.mp
Figure fig2c_espace1



beginfig(1);
%representation d'un plan
numeric u;
pair t,r;
transform T,S;
path p;

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;

%on place les points du parallèlogramme représentant le plan
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;


p:=z0--z1--z3--z2--cycle;

fill p withcolor bleu_ciel;

%on trace le parallèlogramme
draw z0--z2;
draw z2--z3;

%on donne un effet d'epaisseur en changeant l'epaisseur du stylo
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;

%on rechange l'epaisseur du stylo
pickup pencircle scaled 0.5pt;

%on indique le nom du plan
label.urt(btex $P$ etex, z0+(0.1u,0u));
endfig;





Figure fig2c_espace2: figfig2c_espace2.mp
Figure fig2c_espace2



beginfig(2);
%intersection de deux plans
numeric u;
pair t,r;
transform T,S;
path p[],q[];

u= 1cm;

%Tracé de P
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;

z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;

path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;



draw z0--z2;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%Tracé de Q
z5 = 0.5[z0,z1];
z6 = z5 transformed S;
z7 = (2.5u,-1u);
z8 = z7 transformed S;
z5 = 0.5[z9,z7];
z10= z9 transformed S;
p1 = z2--z6;
q1= z9--z10;
z11 = p1 intersectionpoint q1;
p2 = z7--z8;
q2= z5--z1;
z12 = p2 intersectionpoint q2;


path pp;
pp=z7--z8--z10--z9--cycle;
fill pp withcolor green;
%fillcolor:=green;
%transparence pp;


path ppp;
ppp:=z5--z6--z11--z9--cycle;
fill ppp withcolor (green+.55*bleu_ciel);


path Pp;
Pp:=z5--z12--z8--z6--cycle;
fill Pp withcolor (green +.75*bleu_ciel);

draw z5--z6 withcolor bleu; %ici on trace la droite d'intersection
draw z9--z7;
draw z9--z10;
draw z10--z6;
draw z6--z3;
draw z6--z8 dashed evenly;

draw z11--z6 dashed evenly;
draw z2--z11;
draw z5--z12 withpen pencircle scaled 2pt;
draw z12--z8 dashed evenly;
draw z7--z12;
label.rt(btex $Q$ etex, z9);

%nom de la droite d'intersection
label.rt(btex $d$ etex, 0.5[z5,z6])withcolor bleu;
endfig;







Figure fig2c_espace3: figfig2c_espace3.mp
Figure fig2c_espace3



beginfig(3);
%representation d'un plan defini par trois points
numeric u;
pair t,r;
transform T,S;

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;

%tracé du plan
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;


path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;


draw z0--z2;
draw z2--z3;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%tracé des points
dotlabel.top(btex $A$ etex, (2u,1.5u));
dotlabel.top(btex $B$ etex, (1u,.5u));
dotlabel.top(btex $C$ etex, (3u,1u));
endfig;




Figure fig2c_espace4: figfig2c_espace4.mp
Figure fig2c_espace4




beginfig(4);
%representation d'un plan defini par deux droites secantes
numeric u;
pair t,r;
transform T,S;

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;

%tracé du plan
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;




path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;




draw z0--z2;
draw z2--z3;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%tracé des droites
z4 = (0.8u,1u); z5 =(4u,1.5u);draw z4--z5;
z6 = (1u,1.6u);z7=(3.6u,0.4u);draw z6--z7;
label.rt(btex $d$ etex, z5);
label.rt(btex $d'$ etex, z7);
endfig;




Figure fig2c_espace5: figfig2c_espace5.mp
Figure fig2c_espace5



beginfig(5);
%representation d'un plan defini par un point et une droite
numeric u;
pair t,r;
transform T,S;

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;

%tracé du plan
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;


path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;


draw z0--z2;
draw z2--z3;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%le point et la droite
dotlabel.top(btex $A$ etex, (2u,1.5u));
z4 = (1u,.5u);
z5 = (3u,1u);
draw z4--z5;
label.top(btex $d$ etex, z5);
endfig;





Figure fig2c_espace6: figfig2c_espace6.mp
Figure fig2c_espace6




beginfig(6);
%representation d'un plan defini par deux droites parallèles
numeric u;
pair t,r;
transform T,S;

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;

%tracé du plan
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;



path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;



draw z0--z2;
draw z2--z3;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%les deux droites
z4 = (1u,1.3u); z5 =(3u,1.8u);draw z4--z5;
z6 = (1.5u,0.2u);z7 = z6 shifted (z5-z4);draw z6--z7;
label.rt(btex $d$ etex, z5);
label.rt(btex $d'$ etex, z7);
endfig;




Figure fig2c_espace7: figfig2c_espace7.mp
Figure fig2c_espace7




beginfig(7);
%representation de deux droites non parallelles et sans point commun
numeric u;
pair t,r;
transform T,S;

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;
path p[];

%tracé du plan
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;


path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;


draw z0--z2;
draw z2--z3;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%tracé de la droite
z4 = (0.5u,.5u);
z5 = (4u,1u);
draw z4--z5;
label.top(btex $d$ etex, z5);

%tracé du point
z6 = (2u,1.5u);
z7 = (0.2u,1u);
dotlabel.rt(btex $A$ etex, z6);

%on met en place les pointillés
z9 = z6 shifted 2z7;
z10 = z6 shifted -3z7;
p1 = z6--z10;
p2 = z0--z1;
z11 = p1 intersectionpoint p2;
draw z6--z11 dashed evenly;
draw z11--z10;
draw z6--z9;

%le nom de la droite
label.rt(btex $d'$ etex, z10);
endfig;




Figure fig2c_espace8: figfig2c_espace8.mp
Figure fig2c_espace8



beginfig(8);
%representation d'un plan
numeric u;
pair t,r;
transform T,S;
path p[],q[];
u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;

%Trace de P
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;



path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;



draw z0--z2;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%Trace de Q
z4=(0u,-2.2u);
z5 = z4 transformed T;
z6 = z4 transformed S;
z7 = z4 transformed T transformed S;


path pp;
pp:=z4--z5--z7--z6--cycle;
fill pp withcolor 1.2*green;



draw z4--z6;
pickup pencircle scaled 2pt;
draw z4--z5;
draw z5--z7;
pickup pencircle scaled 0.5pt;
label.urt(btex $Q$ etex, z4+(0.1u,0u));

%Plan d'intersection
z8=1/5[z0,z1]+1/2[z0,z2];
z9=3/5[z4,z5]+1/2[z6,z4];

z10 = z8 transformed S;

z11 = z9 transformed S;
p1 = z10--z11;
q1 = z2--z3;
q2 = z0--z1;
q3 = z6--z7;
z12 = p1 intersectionpoint q1;
z13 = p1 intersectionpoint q2;
z14 = p1 intersectionpoint q3;

p2 = z8--z10;
z15 = p2 intersectionpoint q1;

p3 = z8--z9;
z16 = p3 intersectionpoint q2;
z17 = p3 intersectionpoint q3;
q4 = z4--z5;
z18 = p3 intersectionpoint q4;

p4 = z9--z11;
z19 = p4 intersectionpoint q4;


path k[];

k[1]:=z8--z10--z11--z9--cycle;
fill k[1] withcolor rose;


k[2]:=z8--z15--z12--z16--cycle;
fill k[2] withcolor (.75rose+.15bleu_ciel);



k[3]:=z16--z13--z12--cycle;
fill k[3] withcolor (.75rose+.35bleu_ciel);


k[4]:=z18--z17--z14--z19--cycle;
fill k[4] withcolor (.75rose+.25green);


k[5]:=z18--z19--z11--z14--cycle;
fill k[5] withcolor (.45rose+.45green);


draw z9--z19;draw z19--z11 dashed evenly;


draw z8--z9;
draw z8--z10;
draw z10--z12; draw z12--z13 dashed evenly;draw z13--z14;draw z14--z11 dashed evenly;
draw z2--z15; draw z15--z12 dashed evenly;draw z12--z3;
draw z16--z12;
draw z6--z17;draw z17--z14 dashed evenly;draw z14--z7;
draw z18--z14;

pickup pencircle scaled 2pt;
draw z4--z5;
draw z0--z1;

%nom des droites d'intersection
label.rt(btex $d$ etex, 0.5[z12,z16]);
label.rt(btex $d'$ etex, 0.5[z18,z14]);
endfig;




Figure fig2c_espace9: figfig2c_espace9.mp
Figure fig2c_espace9



beginfig(9);
%droite parallele a deux plans secants
numeric u;
pair t,r;
transform T,S;
path p[];

u= 1cm;
t=(4u,1u); r=(0u,2u);
T = identity shifted t;
S = identity shifted r;

%Plan P
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;


path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;


draw z0--z2;
draw z2--z3;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%Plan Q
z4=0.5[z0,z1];
z5 = z4 transformed S;

z6 = z4 shifted (1.5u,-1u);
z4=0.5[z6,z7];
z8 = z6 transformed S;
z9 = z7 transformed S;

p1= z4--z1;
p2 = z6--z8;
z10 = p1 intersectionpoint p2;

p3 = z2--z3; p4 = z9--z7;
z11 = p3 intersectionpoint p4;



path k[];

k[1]:=z8--z9--z7--z6--cycle;
fill k[1] withcolor green;


k[2]:=z11--z5--z4--z7--cycle;
fill k[2] withcolor (.75bleu_ciel+green);



k[3]:=z5--z8--z10--z4--cycle;
fill k[3] withcolor (green+.55bleu_ciel);

draw z5--z11;


draw z11--z9;draw z11--z7 dashed evenly; draw z7--z4 dashed evenly;
label.lft(btex $Q$ etex, z6+(0u,0.5u));
draw z4--z5 withcolor red;
label.lft(btex $\Delta$ etex,0.5[z4,z5])withcolor red;
draw z0--z4;draw z4--z6;draw z6--z8;draw z8--z9;draw z4--z7 dashed evenly;
draw z4--z10 dashed evenly;draw z10--z1;

%droite parallele aux deux plans
z12 = (-1u,0u);
z13 = z12 shifted (0u,3u);
draw z13--z12 withcolor red;
label.lft(btex $d$ etex, z12)withcolor red;
endfig;





Figure fig2c_espace10: figfig2c_espace10.mp
Figure fig2c_espace10



beginfig(10);
%theoreme du toit
numeric u;
pair t,r,v;
transform T,S,V;
path p[];

u= 1cm;
t=(3u,2u); r=(-2u,1.5u);v=(-3u,0u); 
T = identity shifted t;
S = identity shifted r;
V = identity shifted v;
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed S transformed T;
z4 = z0 transformed V;
z5 = z0 transformed V transformed T;

z101=0.1[z0,z1]; z10=0.9[z0,z1];
z23 = z101 transformed S; z32=z10 transformed S;
z45 = z101 transformed V; z54=z10 transformed V;

p1 = z101--z23; p2 = z4--z5;
z11 = p1 intersectionpoint p2;


path k[];

k[1]:=z45--z54--z32--z23--cycle;
fill k[1] withcolor green;



k[3]:=z23--z101--z10--z32--cycle;
fill k[3] withcolor bleu_ciel;

k[2]:=z23--z32--z54--z11--cycle;
fill k[2] withcolor (.75bleu_ciel+green);







draw z0--z1 ;
draw z2--z3 withcolor red;


%pour un exemple de mise en couleur
draw z101--z23 ; draw z10--z32 ;
draw z23--z45 ; draw z32--z54 dashed evenly ;

draw z4--z11 ;
draw z11--z5 dashed evenly ;

label.rt(btex $d$ etex, z0);
label.rt(btex $d'$ etex, z4);
label.top(btex $\Delta$ etex, z2);

endfig;





Figure fig2c_espace11: figfig2c_espace11.mp
Figure fig2c_espace11



beginfig(11);
% plans paralleles a l'aide de droites secantes
numeric u;
pair t,r;
transform T,S;

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;

%premier plan P
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;


path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;


draw z0--z2;
draw z2--z3;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%droites secantes
z4 = (0.8u,1u); z5 =(4u,1.5u);draw z4--z5;
z6 = (1u,1.6u);z7=(3.6u,0.4u);draw z6--z7;
label.rt(btex $d$ etex, z5);
label.rt(btex $d'$ etex, z7);

%deuxieme plan Q
z10=(0u,-2.5u);
z11 = z10 transformed T;
z12 = z10 transformed S;
z13 = z10 transformed T transformed S;


path pP;
pP:=z10--z11--z13--z12--cycle;
fill pP withcolor green;


draw z10--z12;
draw z12--z13;
pickup pencircle scaled 2pt;
draw z10--z11;
draw z11--z13;
pickup pencircle scaled 0.5pt;
label.urt(btex $Q$ etex, z10+(0.1u,0u));

%droites secantes
z14 = (0.8u,-1.5u); z15 =(4u,-1u);draw z14--z15;
z16 = (1u,-0.9u);z17=(3.6u,-2.1u);draw z16--z17;
label.rt(btex $d_{1}$ etex, z15);
label.rt(btex $d'_{1}$ etex, z17);
endfig;





Figure fig2c_espace12: figfig2c_espace12.mp
Figure fig2c_espace12




beginfig(12);
% parallelisme plan et droite
numeric u;
pair t,r;
transform T,S;

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;

%plan
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;


path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;


draw z0--z2;
draw z2--z3;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%droite dans le plan
z4 = (1u,.5u);
z5 = (4u,1u);
draw z4--z5;
label.top(btex $d'$ etex, z4);

%la droite en dehors du plan
z6 = (1u,2.5u);
z7 = z6 shifted z5-z4;
draw z6--z7;
label.top(btex $d$ etex, z6);
endfig;




Figure fig2c_espace13: figfig2c_espace13.mp
Figure fig2c_espace13




beginfig(13);
%droites orthogonales 
numeric u;
pair t,r;
transform T,S;

u= 1cm;
t=(2u,3u); r=(0u,2u);
T = identity shifted t;
S = identity shifted r;

%les droites perpendiculaires en I
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
draw z0--z1;
draw z0--z2;
label.bot(btex $I$ etex, z0);

%marquage de l'angle droit
z3=0.1[z0,z1];z4=0.1[z0,z2];
z5=z3 shifted z4-z0;
draw z3--z5;
draw z4--z5;

%droites d et delta
z6=(0u,-1u);
z7 = z6 transformed T;
draw z7--z6;
label.bot(btex $\Delta$ etex, z7);
z8=(-1u,-1u);
z9= z8 transformed S;
label.lft(btex $d$ etex, z9);
draw z9--z8;
endfig;




Figure fig2c_espace14: figfig2c_espace14.mp
Figure fig2c_espace14



beginfig(14);
%droite orthogonale a un plan
numeric u;
pair t,r;
transform T,S;
path p[];

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;

%plan P
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;



path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;

draw z0--z2;
draw z2--z3;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%droites secantes
z4 = (0.8u,1u); z5 =(4u,1.5u);draw z4--z5;
z6 = (1u,1.6u);z7=(3.6u,0.4u);draw z6--z7;
label.rt(btex $d$ etex, z5);
label.rt(btex $d'$ etex, z7);
p1 = z4--z5;p2 = z6--z7;

%droite orthogonale
z8 = p1 intersectionpoint p2;
z9 = z8 shifted (0u,2u);
label.rt(btex $\Delta$ etex, z9);
draw z8--z9;
z10 = z8 shifted (0u,-2u);
p3 = z9--z10;p4 = z0--z1;
z11 = p3 intersectionpoint p4;
draw z8--z11 dashed evenly;draw z11--z10;

%marquage des angles droits
z12=0.1[z8,z7];z13=0.1[z8,z9];
z14= z13 shifted z12-z8;
draw z12--z14;
draw z13--z14;

z15=0.2[z8,z4];z16=0.1[z8,z9];
z17= z16 shifted z15-z8;
draw z15--z17;
draw z16--z17;
endfig;







Figure fig2c_espace15: figfig2c_espace15.mp
Figure fig2c_espace15



beginfig(15);
%plans paralleles et droite orthogonale
numeric u;
pair t,r;
transform T,S;

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;
path p[];

%premier plan et droites
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;



path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;

draw z0--z2;
draw z2--z3;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));

%droites secantes
z4 = (0.8u,1u); z5 =(4u,1.5u);draw z4--z5;
z6 = (1u,1.6u);z7=(3.6u,0.4u);draw z6--z7;
label.rt(btex $d$ etex, z5);
label.rt(btex $d'$ etex, z7);

%deuxieme plan et droites
z10=(0u,-2.5u);
z11 = z10 transformed T;
z12 = z10 transformed S;
z13 = z10 transformed T transformed S;


path Pp;
Pp:=z10--z11--z13--z12--cycle;
fill Pp withcolor green;


draw z10--z12;
draw z12--z13;
pickup pencircle scaled 2pt;
draw z10--z11;
draw z11--z13;
pickup pencircle scaled 0.5pt;
label.urt(btex $Q$ etex, z10+(0.1u,0u));

%droites secantes
z14 = (0.8u,-1.5u); z15 =(4u,-1u);draw z14--z15;
z16 = (1u,-0.9u);z17=(3.6u,-2.1u);draw z16--z17;
label.rt(btex $d_{1}$ etex, z15);
label.rt(btex $d'_{1}$ etex, z17);

%droite orthogonale
p1=z4--z5;p2=z6--z7;
p3=z14--z15;p4=z16--z17;
p5=z0--z1;p6=z10--z11;
z20 = p1 intersectionpoint p2;
z21 = p3 intersectionpoint p4;

p7 = z20--z21;
z22 = p7 intersectionpoint p5;

z24 = z20 shifted (0u,1.5u);
z25 = z21 shifted (0u,-1.5u);
p8 = z21--z25;
z23 = p8 intersectionpoint p6;
draw z24--z20;draw z20--z22 dashed evenly; draw z22--z21; 
draw z21--z23 
dashed evenly; draw z23--z25;
label.rt(btex $\Delta$ etex, z24);

%marquage des angles droits

z30=0.2[z20,z4];z31=0.1[z20,z24];
z32 = z31 shifted z30-z20;
draw z32--z30;
draw z32--z31;

z40=0.2[z21,z14];z41=0.1[z21,z22];
z42 = z41 shifted z40-z21;
draw z42--z40;
draw z42--z41;

z50=0.1[z20,z7];z51=0.1[z20,z24];
z52 = z51 shifted z50-z20;
draw z52--z50;
draw z52--z51;

z60=0.1[z21,z17];z61=0.1[z21,z22];
z62 = z61 shifted z60-z21;
draw z62--z60;
draw z62--z61;
endfig;






Figure fig2c_espace16: figfig2c_espace16.mp
Figure fig2c_espace16




beginfig(16);
%droites orthogonales a deux plans paralleles

numeric u;
pair t,r;
transform T,S;

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;
path p[];

%premier plan
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;

path p;
p:=z0--z1--z3--z2--cycle;
fill p withcolor bleu_ciel;

draw z0--z2;
draw z2--z3;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));


%deuxieme plan 
z10=(0u,-2.5u);
z11 = z10 transformed T;
z12 = z10 transformed S;
z13 = z10 transformed T transformed S;


path pP;
pP:=z10--z11--z13--z12--cycle;
fill pP withcolor green;


draw z10--z12;
draw z12--z13;
pickup pencircle scaled 2pt;
draw z10--z11;
draw z11--z13;
pickup pencircle scaled 0.5pt;
label.urt(btex $Q$ etex, z10+(0.1u,0u));

%premiere droite
z20 = (2u,1u);z26 = z20 shifted (0u,-2.5u);
z21 = z20 shifted (0u,2u);
z22 = z20 shifted (0u,-4.5u);

p1 = z21--z22;
p2 = z0--z1;
p3 = z10--z11;
z24 = p1 intersectionpoint p2;
z25 = p1 intersectionpoint p3;
draw z21--z20;draw z20--z24 dashed evenly;draw z24--z26;draw z26--z25 
dashed evenly; draw z25--z22;

%deuxieme droite
z30 = (3u,1.5u);z36 = z30 shifted (0u,-2.5u);
z31 = z30 shifted (0u,2u);
z32 = z30 shifted (0u,-4.5u);

p11 = z31--z32;
p12 = z0--z1;
p13 = z10--z11;
z34 = p11 intersectionpoint p12;
z35 = p11 intersectionpoint p13;
draw z31--z30;draw z30--z34 dashed evenly;draw z34--z36;draw z36--z35 
dashed evenly; draw z35--z32;

%marquage des angles droits
z40=0.1[z20,z30];z41=0.1[z20,z21];
z42 = z41 shifted z40-z20;
draw z42--z40;
draw z42--z41;

z50=0.1[z30,z20];z51=0.1[z30,z31];
z52 = z51 shifted z50-z30;
draw z52--z50;
draw z52--z51;

z60=0.1[z26,z36];z61=0.1[z26,z24];
z62 = z61 shifted z60-z26;
draw z62--z60;
draw z62--z61;

z70=0.1[z36,z26];z71=0.2[z36,z34];
z72 = z71 shifted z70-z36;
draw z72--z70;
draw z72--z71;

draw z20--z30;
draw z26--z36;
endfig;





Figure fig2c_espace17: figfig2c_espace17.mp
Figure fig2c_espace17



beginfig(17);
%intersection de deux plans perpendiculaires
numeric u;
pair t,r;
transform T,S;
path p[],q[];

u= 1cm;
t=(4u,0u); r=(1u,2u);
T = identity shifted t;
S = identity shifted r;

%Tracé de P
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;
draw z0--z2;
pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;


%Tracé de Q
z5 = 0.5[z0,z1];
z6 = z5 transformed S;
z7 = z5 shifted (0u,-2.5u);
z8 = z7 transformed S;
z5 = 0.5[z9,z7];
z10= z9 transformed S;

p1 = z2--z6;
q1= z5--z9;
z11 = p1 intersectionpoint q1;

p2 = z6--z8;
q2= z5--z1;
z12 = p2 intersectionpoint q2;





path k[];

k[1]:=z7--z8--z10--z9--cycle;
fill k[1] withcolor green;



k[3]:=z0--z1--z3--z2--cycle;
fill k[3] withcolor bleu_ciel;

k[2]:=z11--z6--z5--cycle;
fill k[2] withcolor (.55bleu_ciel+green);


k[4]:=z5--z12--z6--cycle;
fill k[4] withcolor (.75bleu_ciel+green);

draw z0--z1--z3 withpen pencircle scaled 2pt;
label.urt(btex $P$ etex, z0+(0.1u,0u));
draw z5--z6 withcolor red; 
draw z9--z7;
draw z9--z10;
draw z10--z6;
draw z6--z3;
draw z7--z8;

draw z11--z6 dashed evenly;
draw z2--z11;

draw z12--z6 dashed evenly;
draw z8--z12;
label.rt(btex $Q$ etex, z9);

%nom de la droite d'intersection
label.rt(btex $d$ etex, 0.6[z5,z6])withcolor red;
%droites orthogonales
z13=0.5[z5,z6];
z14 = z13 shifted (0u,2u);
z15 = z13 shifted (0u,-2u);
p3 = z0--z1;
q3 = z13--z15;
z16 = p3 intersectionpoint q3;
draw z14--z13;
draw z13--z16 dashed evenly;
draw z16--z15;
%marquage de l'angle droit
z20=0.2[z13,z6];z21=0.2[z13,z14];
z22 = z21 shifted z20-z13;
draw z22--z20;
draw z22--z21;

z17 = z13 shifted 0.8(z1-z5);
z18 = z13 shifted 0.8(z0-z5);
p4 = z13--z18;
z19 = q1 intersectionpoint p4;
draw z18--z19;
draw z19--z13 dashed evenly;
draw z13--z17;
%marquage de l'angle droit
z30=0.1[z13,z18];z31=0.1[z13,z14];
z32 = z31 shifted z30-z13;
draw z32--z30;
draw z32--z31;
endfig;






Figure fig2c_espace18: figfig2c_espace18.mp
Figure fig2c_espace18



beginfig(18);
%plans perpendiculaires a un meme plan
numeric u;
pair t,r;
transform T,S;
path p[],q[];
u= 1cm;
t=(5u,0u); r=(1u,2.3u);
T = identity shifted t;
S = identity shifted r;

%plan Q
z0=(0u,0u);
z1 = z0 transformed T;
z2 = z0 transformed S;
z3 = z0 transformed T transformed S;

%les plans perpendiculaires
z4= 1/4[z0,z1]; z5= 3/4[z0,z1]; z6= 1/2[z4,z5]; 
z7 =  z6 shifted (0u,1u);

z8 = z4 shifted (0u,2u);
z9 = z5 shifted (0u,2u);
z10 = z7 shifted (0u,2u);
z4=0.5[z8,z11];z5=0.5[z12,z9];z7=0.5[z13,z10];

p1 = z2--z3;
q1 = z8--z10;q2=z9--z10;
z14= p1 intersectionpoint q1;
z15= p1 intersectionpoint q2;

z16=1/2[z14,z15];


path k[];

k[1]:=z0--z1--z3--z2--cycle;
fill k[1] withcolor green;



k[3]:=z8--z11--z13--z10--cycle;
fill k[3] withcolor bleu_ciel;

k[2]:=z10--z13--z12--z9--cycle;
fill k[2] withcolor rose;

k[4]:=z8--z14--z16--z7--z4--cycle;
fill k[4] withcolor(green +.75bleu_ciel);

k[5]:=z4--z7--z6--cycle;
fill k[5] withcolor(green+.55bleu_ciel);

k[6]:=z5--z7--z16--z15--z9--cycle;
fill k[6] withcolor(.25green +.75rose);

k[7]:=z5--z7--z6--cycle;
fill k[7] withcolor(.45green+.45rose);





draw z0--z2;

pickup pencircle scaled 2pt;
draw z0--z1;
draw z1--z3;
pickup pencircle scaled 0.5pt;
label.urt(btex $Q$ etex, z0+(0.1u,0u));

draw z4--z7;
draw z5--z7;

draw z8--z11;draw z8--z10;
draw z12--z9;draw z9--z10;
draw z7--z10;
draw z7--z6 dashed evenly;
draw z6--z13;
draw z11--z13; draw z13--z12;


draw z2--z14;draw z14--z15 dashed evenly; draw z15--z3;

%marquage des angles droits;
z20=0.1[z7,z10];z21=0.2[z7,z4];
z22 = z21 shifted z20-z7;
draw z22--z20;
draw z22--z21;

z30=0.1[z7,z10];z31=0.2[z7,z5];
z32 = z31 shifted z30-z7;
draw z32--z30;
draw z32--z31;

label.bot(btex $P$ etex, z11+(0.2u,0.6u));
label.bot(btex $P'$ etex, z12+(-0.2u,0.8u));
endfig;