Fichier section.mp (figure 20) — Modifié le 20 Juin 2008 à 22 h 15
Source
vardef cube (expr depart,dimarete) =
save fig,cube,chemin;
pair sommetCube[];
path chemin;
picture fig,cube;
fig=currentpicture;
currentpicture:=nullpicture;
sommetCube0=depart;
sommetCube1=sommetCube0 shifted (dimarete,0);
(sommetCube3-sommetCube0)=(sommetCube1-sommetCube0) scaled .5 rotated 35;
(sommetCube2-sommetCube1)=(sommetCube0-sommetCube1) scaled .5 rotated (-145);
for i:=0 upto 3 :
sommetCube[i+4]=sommetCube[i] shifted (0,dimarete);
endfor
draw sommetCube0--sommetCube1--sommetCube2--sommetCube6--
sommetCube5--sommetCube4--cycle;
draw sommetCube1--sommetCube5;
draw sommetCube0--sommetCube3--sommetCube7 dashed evenly;
draw sommetCube2--sommetCube3 dashed evenly;
draw sommetCube4--sommetCube7--sommetCube6;
cube=currentpicture;
currentpicture:=fig;
cube
enddef;
vardef nommecube =
label.llft(btex $A$ etex, sommetCube0);
label.lrt(btex $B$ etex, sommetCube1);
label.rt(btex $C$ etex, sommetCube2);
label.urt(btex $D$ etex, sommetCube3);
label.ulft(btex $E$ etex, sommetCube4);
label.top(btex $F$ etex, sommetCube5);
label.urt(btex $G$ etex, sommetCube6);
label.ulft(btex $H$ etex, sommetCube7);
enddef;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%TETRAEDRE
pickup pencircle scaled 0.8bp;
vardef tetraedreABCD =
u:=2cm;
pair A,B,C,D;
B:=(0,0); D:=(2*u,0); C:=(0.8*u,-0.8*u); A:=(1*u,1.2*u);
draw A--C--B--A--D--C;
draw B--D dashed evenly;
label.top(btex $A$ etex, (1*u,1.2*u));
label.llft(btex $B$ etex, (0,0));
label.bot(btex $C$ etex, (0.8*u,-0.8*u));
label.lrt(btex $D$ etex, (2*u,0));
enddef;
%%%%%%%%%%
beginfig(1); %% Un tétraedre.
%pair I,J,K,M[];
%pair A,B,C,D;
%B:=(0,0); D:=(2*u,0); C:=(0.8*u,-0.8*u); A:=(1*u,1.2*u);
%tetraedre;
tetraedreABCD;
%I:=1/4[A,D];
%J:=1/2[A,C];
%K:=1/4[B,C];
%dotlabel.urt(btex $I$ etex,I);
%dotlabel.lrt(btex $J$ etex,J);
%dotlabel.bot(btex $K$ etex,K);
endfig;
beginfig(2);
%Tracé de la section au 3
pair I,J,K,M[];
pair A,B,C,D;
B:=(0,0); D:=(2*u,0); C:=(0.8*u,-0.8*u); A:=(1*u,1.2*u);
%tetraedre;
tetraedreABCD;
I:=1/4[A,D];
J:=1/2[A,C];
K:=1/3[B,C];
dotlabel.urt(btex $I$ etex,I);
dotlabel.lrt(btex $J$ etex,J);
dotlabel.llft(btex $K$ etex,K);
endfig;
beginfig(3); %Tracé de la section du 2.
pair I,J,K,M[];
pair A,B,C,D;
B:=(0,0); D:=(2*u,0); C:=(0.8*u,-0.8*u); A:=(1*u,1.2*u);
%tetraedre;
tetraedreABCD;
I:=1/4[A,D];
J:=1/2[A,C];
K:=1/3[B,C];
dotlabel.urt(btex $I$ etex,I);
dotlabel.lrt(btex $J$ etex,J);
dotlabel.llft(btex $K$ etex,K);
%%%%%%%
%% DEBUT section %%
M1=whatever[I,J]=whatever[C,D];
M2=whatever[M1,K]=whatever[B,D];
draw I--J--K withcolor red;
draw K--M2--I withcolor red dashed evenly;
draw K--M1--J dashed evenly scaled 0.5;
draw M1--C dashed evenly scaled 0.5;
endfig;
%%%%%%%%__________________________________________________________________
beginfig(4); %Tetraedre, tracé de la section au 5
pair I,J,K,M[];
pair A,B,C,D;
B:=(0,0); D:=(2*u,0); C:=(0.8*u,-0.8*u); A:=(1*u,1.2*u);
tetraedreABCD;
I:=3/4[A,D];
J:=1/3[A,C];
K:=1/3[B,C];
dotlabel.urt(btex $I$ etex,I);
dotlabel.ulft(btex $J$ etex,J);
dotlabel.llft(btex $K$ etex,K);
endfig;
%%%%%%%%__________________________________________________________________
beginfig(5);
%Tracé de la section du 4
pair I,J,K,M[];
pair A,B,C,D;
B:=(0,0); D:=(2*u,0); C:=(0.8*u,-0.8*u); A:=(1*u,1.2*u);
%tetraedre;
tetraedreABCD;
I:=3/4[A,D];
J:=1/3[A,C];
K:=1/3[B,C];
dotlabel.urt(btex $I$ etex,I);
dotlabel.ulft(btex $J$ etex,J);
dotlabel.llft(btex $K$ etex,K);
%%%%%%%
%% DEBUT section %%
M1=whatever[I,J]=whatever[C,D];
M2=whatever[M1,K]=whatever[B,D];
draw I--J--K withcolor red;
draw K--M2--I withcolor red dashed evenly;
draw I--M1--M2 dashed evenly scaled 0.5;
draw M1--C dashed evenly scaled 0.5;
endfig;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
beginfig(6); %Pyramide, section corrigée au 7
pair I,J,K,M[];
pair A,B,C,D,E;
B:=(0,0); E:=(2.5*u,0); C:=(0.7*u,-0.8*u); A:=(1*u,1.2*u); D:=(1.8*u,-u);
draw D--A--B--C--D--E--A--C;
draw B--E dashed evenly;
label.top(btex $A$ etex, A);
label.llft(btex $B$ etex, B);
label.bot(btex $C$ etex, C);
label.lrt(btex $D$ etex, D);
label.lrt(btex $E$ etex, E);
I:=4/10[A,B];
J:=7/10[A,C];
K:=4/5[A,E];
dotlabel.ulft(btex $I$ etex,I);
dotlabel.urt(btex $J$ etex,J);
dotlabel.urt(btex $K$ etex,K);
endfig;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
beginfig(7); %% Pyramide avec section du 6
pair I,J,K,M[];
pair A,B,C,D,E;
B:=(0,0); E:=(2.5*u,0); C:=(0.7*u,-0.8*u); A:=(1*u,1.2*u); D:=(1.8*u,-u);
draw D--A--B--C--D--E--A--C;
draw B--E dashed evenly;
label.top(btex $A$ etex, A);
label.llft(btex $B$ etex, B);
label.bot(btex $C$ etex, C);
label.lrt(btex $D$ etex, D);
label.lrt(btex $E$ etex, E);
I:=4/10[A,B];
J:=7/10[A,C];
K:=4/5[A,E];
dotlabel.ulft(btex $I$ etex,I);
dotlabel.urt(btex $J$ etex,J);
dotlabel.urt(btex $K$ etex,K);
%%%%%%%
%% DEBUT section %%
M1=whatever[I,J]=whatever[C,B];
M2=whatever[I,K]=whatever[B,E];
M3=whatever[M1,M2]=whatever[E,D];
M4=whatever[M1,M2]=whatever[C,D];
%draw C--M1--M2--E dashed evenly scaled 0.5;
draw C--M1--M4 dashed evenly scaled 0.5;
draw M3--M2--E dashed evenly scaled 0.5;
draw M1--J dashed evenly scaled 0.5;
draw M2--K dashed evenly scaled 0.5;
draw I--J--M4 withcolor red;
draw K--M3 withcolor red;
draw K--I withcolor red dashed evenly;
draw M3--M4 withcolor red dashed evenly;
endfig;
beginfig(8); %Section corrigée au 9
picture lecube;
pair A,B,H,F,C,I,E,G,J,K,D, M[];
pickup pencircle scaled 0.8bp;
lecube:=cube(origin,4cm);
draw lecube;
nommecube;
A:=sommetCube0;
B=sommetCube1;
E:=sommetCube4;
H:=sommetCube7;
G:=sommetCube6;
F:=sommetCube5;
C:=sommetCube2;
%pickup pencircle scaled 2bp;
I=1/4[E,H];
J=1/2[A,B];
K=1/4[G,F];
dotlabel.ulft(btex $I$ etex,I);
dotlabel.bot(btex $J$ etex,J);
dotlabel.lrt(btex $K$ etex,K);
endfig;
beginfig(9); %Solution du 8
picture lecube;
pair A,B,H,F,C,I,E,G,J,K, M[];
pickup pencircle scaled 0.8bp;
lecube:=cube(origin,4cm);
draw lecube;
nommecube;
A:=sommetCube0;
B=sommetCube1;
E:=sommetCube4;
H:=sommetCube7;
G:=sommetCube6;
F:=sommetCube5;
C:=sommetCube2;
%pickup pencircle scaled 2bp;
I=1/4[E,H];
J=1/2[A,B];
K=1/4[G,F];
%draw I;
dotlabel.ulft(btex $I$ etex,I);
dotlabel.bot(btex $J$ etex,J);
dotlabel.lrt(btex $K$ etex,K);
%%%%%% Tracé de la section:
M1=whatever[I,K]=whatever[E,F];
%M2=whatever[I,K]=whatever[H,G];
draw M1--I dashed evenly scaled 0.5;
draw M1--E dashed evenly scaled 0.5;
%draw M2--G dashed evenly scaled 0.5;
M3=whatever[M1,J]=whatever[E,A];
draw M1--M3 dashed evenly scaled 0.5;
M4=whatever[M3,J]=whatever[B,F];
M5=whatever[M4,K]=whatever[B,C];
draw J--M4--B dashed evenly scaled 0.5;
draw M4--M5 dashed evenly scaled 0.5;
%polygone de section en rouge
draw J--M3 withcolor red;
draw I--K--M5 withcolor red;
draw M3--I withcolor red dashed evenly;
draw M5--J withcolor red dashed evenly;
endfig;
beginfig(10); %Section corrigée au 11
picture lecube;
pair A,B,H,F,C,I,E,G,J,D,K, M[];
pickup pencircle scaled 0.8bp;
lecube:=cube(origin,4cm);
draw lecube;
nommecube;
A:=sommetCube0;
B=sommetCube1;
E:=sommetCube4;
H:=sommetCube7;
G:=sommetCube6;
F:=sommetCube5;
C:=sommetCube2;
D:=sommetCube3;
%pickup pencircle scaled 2bp;
I=2/3[E,H];
J=1/2[A,B];
K=3/4[G,F];
dotlabel.ulft(btex $I$ etex,I);
dotlabel.bot(btex $J$ etex,J);
dotlabel.top(btex $K$ etex,K);
endfig;
beginfig(11); %Solution du 10
picture lecube;
pair A,B,H,F,C,I,E,G,J,D,K, M[];
pickup pencircle scaled 0.8bp;
lecube:=cube(origin,4cm);
draw lecube;
nommecube;
A:=sommetCube0;
B=sommetCube1;
E:=sommetCube4;
H:=sommetCube7;
G:=sommetCube6;
F:=sommetCube5;
C:=sommetCube2;
D:=sommetCube3;
%pickup pencircle scaled 2bp;
I=2/3[E,H];
J=1/2[A,B];
K=3/4[G,F];
dotlabel.ulft(btex $I$ etex,I);
dotlabel.bot(btex $J$ etex,J);
dotlabel.top(btex $K$ etex,K);
%%%%%% Tracé de la section:
M1=whatever[I,K]=whatever[E,F];
%M2=whatever[I,K]=whatever[H,G];
draw M1--K dashed evenly scaled 0.5;
draw M1--F dashed evenly scaled 0.5;
%draw M2--G dashed evenly scaled 0.5;
M3=whatever[M1,J]=whatever[F,B];
draw M1--M3 dashed evenly scaled 0.5;
M4=whatever[M3,J]=whatever[E,A];
M5=whatever[M4,I]=whatever[A,D];
draw J--M4 dashed evenly scaled 0.5;
draw M4--M5 dashed evenly scaled 0.5;
%polygone de section en rouge
%draw J--M3 withcolor red;
draw I--K--M3--J withcolor red;
draw J--M5--I withcolor red dashed evenly;
%draw M5--J withcolor red dashed evenly;
%pour repérer les points de construction:
%for i:=3 upto 5:
% dotlabel(btex $X$ etex,M[i]);
%endfor;
endfig;
beginfig(12); %solution au 13
picture lecube;
pair A,B,H,F,C,I,E,G,J,D,K, M[];
pickup pencircle scaled 0.8bp;
lecube:=cube(origin,4cm);
draw lecube;
nommecube;
A:=sommetCube0;
B=sommetCube1;
E:=sommetCube4;
H:=sommetCube7;
G:=sommetCube6;
F:=sommetCube5;
C:=sommetCube2;
D:=sommetCube3;
%pickup pencircle scaled 2bp;
I=2/3[E,H];
J=1/2[A,B];
K=2/3[B,C];
dotlabel.ulft(btex $I$ etex,I);
dotlabel.bot(btex $J$ etex,J);
dotlabel.bot(btex $K$ etex,K);
endfig;
beginfig(13); %Solution du 12
picture lecube;
pair A,B,H,F,C,I,E,G,J,D,K, M[];
pickup pencircle scaled 0.8bp;
lecube:=cube(origin,4cm);
draw lecube;
nommecube;
A:=sommetCube0;
B=sommetCube1;
E:=sommetCube4;
H:=sommetCube7;
G:=sommetCube6;
F:=sommetCube5;
C:=sommetCube2;
D:=sommetCube3;
%pickup pencircle scaled 2bp;
I=2/3[E,H];
J=1/2[A,B];
K=2/3[B,C];
dotlabel.ulft(btex $I$ etex,I);
dotlabel.bot(btex $J$ etex,J);
dotlabel.bot(btex $K$ etex,K);
%%%%%% Tracé de la section:
M1=whatever[J,K]=whatever[D,C];
M2=whatever[J,K]=whatever[A,D];
M3=whatever[M2,I]=whatever[A,E];
draw K--M1--C dashed evenly scaled 0.5;
draw A--M2--J dashed evenly scaled 0.5;
draw M2--M3 dashed evenly scaled 0.5;
M4=whatever[M3,I]=whatever[H,D];
draw I--M4--H dashed evenly scaled 0.5;
M5=whatever[M4,M1]=whatever[H,G];
M6=whatever[M4,M1]=whatever[C,G];
draw M4--M5 dashed evenly scaled 0.5;
draw M1--M6 dashed evenly scaled 0.5;
%polygone de section en rouge
%draw J--M3 withcolor red;
draw I--M3--J withcolor red;
draw I--M5 withcolor red;
draw K--M6 withcolor red;
draw J--K withcolor red dashed evenly;
draw J--M3 withcolor red dashed evenly;
draw M5--M6 withcolor red dashed evenly;
%pour repérer les points de construction:
%for i:=3 upto 5:
% dotlabel(btex $X$ etex,M[i]);
%endfor;
endfig;
beginfig(14); %%corrigé au 15
picture lecube;
pair A,B,H,F,C,I,E,G,J,D,K, M[];
pickup pencircle scaled 0.8bp;
lecube:=cube(origin,4cm);
draw lecube;
nommecube;
A:=sommetCube0;
B=sommetCube1;
E:=sommetCube4;
H:=sommetCube7;
G:=sommetCube6;
F:=sommetCube5;
C:=sommetCube2;
D:=sommetCube3;
%pickup pencircle scaled 2bp;
I=2/7[E,F]; %1/4
J=5/7[A,B]; %mettre 5/7 pour le suivant
K=1/3[B,C];
dotlabel.ulft(btex $I$ etex,I);
dotlabel.bot(btex $J$ etex,J);
dotlabel.bot(btex $K$ etex,K);
endfig;
beginfig(15); %Solution du 14
picture lecube;
pair A,B,H,F,C,I,E,G,J,D,K, M[];
pickup pencircle scaled 0.8bp;
lecube:=cube(origin,4cm);
draw lecube;
nommecube;
A:=sommetCube0;
B=sommetCube1;
E:=sommetCube4;
H:=sommetCube7;
G:=sommetCube6;
F:=sommetCube5;
C:=sommetCube2;
D:=sommetCube3;
%pickup pencircle scaled 2bp;
I=2/7[E,F]; %1/4
J=5/7[A,B]; %mettre 5/7 pour le suivant
K=1/3[B,C];
dotlabel.ulft(btex $I$ etex,I);
dotlabel.bot(btex $J$ etex,J);
dotlabel.bot(btex $K$ etex,K);
%%%%%% Tracé de la section:
M1=whatever[J,I]=whatever[B,F];
M2=whatever[M1,K]=whatever[F,G];
%M3=whatever[J,I]=whatever[B,F];
%
draw B--M1 dashed evenly scaled 0.5;
draw K--M1--J dashed evenly scaled 0.5;
%draw M2--M3 dashed evenly scaled 0.5;
%M4=whatever[M3,I]=whatever[H,D];
%draw I--M4--H dashed evenly scaled 0.5;
%M5=whatever[M4,M1]=whatever[H,G];
%M6=whatever[M4,M1]=whatever[C,G];
%draw M4--M5 dashed evenly scaled 0.5;
%draw M1--M6 dashed evenly scaled 0.5;
%polygone de section en rouge
%draw J--M3 withcolor red;
draw I--J withcolor red;
draw I--M2 withcolor red;
draw K--M2 withcolor red;
draw J--K withcolor red dashed evenly;
%draw J--M3 withcolor red dashed evenly;
%draw M5--M6 withcolor red dashed evenly;
%pour repérer les points de construction:
%for i:=3 upto 5:
% dotlabel(btex $X$ etex,M[i]);
%endfor;
endfig;
beginfig(16); %Solution au 17
picture lecube;
pair A,B,H,F,C,I,E,G,J,D,K, M[];
pickup pencircle scaled 0.8bp;
lecube:=cube(origin,4cm);
draw lecube;
nommecube;
A:=sommetCube0;
B=sommetCube1;
E:=sommetCube4;
H:=sommetCube7;
G:=sommetCube6;
F:=sommetCube5;
C:=sommetCube2;
D:=sommetCube3;
%pickup pencircle scaled 2bp;
I=1/4[E,F]; %1/4
J=5/7[A,B];
K=2/3[B,C];
dotlabel.ulft(btex $I$ etex,I);
dotlabel.bot(btex $J$ etex,J);
dotlabel.bot(btex $K$ etex,K);
endfig;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
beginfig(17); %Solution du 16
picture lecube;
pair A,B,H,F,C,I,E,G,J,D,K, M[];
pickup pencircle scaled 0.8bp;
lecube:=cube(origin,4cm);
draw lecube;
nommecube;
A:=sommetCube0;
B=sommetCube1;
E:=sommetCube4;
H:=sommetCube7;
G:=sommetCube6;
F:=sommetCube5;
C:=sommetCube2;
D:=sommetCube3;
%pickup pencircle scaled 2bp;
I=1/4[E,F]; %1/4
J=5/7[A,B];
K=2/3[B,C];
dotlabel.ulft(btex $I$ etex,I);
dotlabel.bot(btex $J$ etex,J);
dotlabel.bot(btex $K$ etex,K);
%%%%%% Tracé de la section:
M1=whatever[J,I]=whatever[B,F];
M2=whatever[M1,K]=whatever[F,G];
M3=whatever[M1,K]=whatever[C,G];
M4=whatever[M2,I]=whatever[H,G];
draw B--M1 dashed evenly scaled 0.5;
draw K--M1--J dashed evenly scaled 0.5;
draw B--M1 dashed evenly scaled 0.5;
draw M2--M3 dashed evenly scaled 0.5;
draw G--M2 dashed evenly scaled 0.5;
draw M2--M4 dashed evenly scaled 0.5;
%
%draw I--M4--H dashed evenly scaled 0.5;
%M5=whatever[M4,M1]=whatever[H,G];
%M6=whatever[M4,M1]=whatever[C,G];
%draw M4--M5 dashed evenly scaled 0.5;
%draw M1--M6 dashed evenl scaled 0.5;
%polygone de section en rouge
%draw J--M3 withcolor red;
draw I--J withcolor red;
draw I--M4 withcolor red;
draw K--M3 withcolor red;
draw J--K withcolor red dashed evenly;
draw M4--M3 withcolor red dashed evenly;
%draw M5--M6 withcolor red dashed evenly;
%pour repérer les points de construction:
%for i:=3 upto 5:
% dotlabel(btex $X$ etex,M[i]);
%endfor;
endfig;
beginfig(18); %Simple pyramide à base quadrilatère qq.
%Demander l'intersection de (ABC)et (ADE)
u:=2cm;
pair A,B,C,D,E;
B:=(0,0); E:=(2.5*u,0); C:=(0.7*u,-0.8*u); A:=(1*u,1.2*u); D:=(1.8*u,-u);
draw D--A--B--C--D--E--A--C;
draw B--E dashed evenly;
label.top(btex $A$ etex, A);
label.llft(btex $B$ etex, B);
label.bot(btex $C$ etex, C);
label.lrt(btex $D$ etex, D);
label.lrt(btex $E$ etex, E);
endfig;
beginfig(19); %Simple pyramide à base quadrilatère qq.
%Demander l'intersection de (ABC)et (ADE)
u:=2cm;
pair A,B,C,D,E,M[];
B:=(0,0); E:=(2.5*u,0); C:=(0.7*u,-0.8*u); A:=(1*u,1.2*u); D:=(1.8*u,-u);
draw D--A--B--C--D--E--A--C;
draw B--E dashed evenly;
label.top(btex $A$ etex, A);
label.llft(btex $B$ etex, B);
label.bot(btex $C$ etex, C);
label.lrt(btex $D$ etex, D);
label.lrt(btex $E$ etex, E);
%% DEBUT intersection %%
M1=whatever[B,C]=whatever[D,E];
draw C--M1--D dashed evenly scaled 0.5;
draw A--M1 withcolor red;
endfig;
beginfig(20); %% Pyramide avec section au 21
pair I,J,K,M[];
pair A,B,C,D,E;
B:=(0,0); E:=(2.5*u,0); C:=(0.7*u,-0.8*u); A:=(1*u,1.2*u); D:=(1.8*u,-u);
draw D--A--B--C--D--E--A--C;
draw B--E dashed evenly;
label.top(btex $A$ etex, A);
label.llft(btex $B$ etex, B);
label.bot(btex $C$ etex, C);
label.lrt(btex $D$ etex, D);
label.lrt(btex $E$ etex, E);
I:=3/10[A,B];
J:=7/10[A,C];
K:=7/10[A,E];
dotlabel.ulft(btex $I$ etex,I);
%dotlabel.urt(btex $J$ etex,J);
dotlabel.urt(btex $K$ etex,K);
%%%%%%%
%% DEBUT section %%
M1=whatever[I,J]=whatever[C,B];
M2=whatever[I,K]=whatever[B,E];
M3=whatever[M1,M2]=whatever[E,D];
M4=whatever[M1,M2]=whatever[C,D];
dotlabel.bot(btex $J$ etex,M4);
endfig;
beginfig(21); %% Pyramide avec section du 20
pair I,J,K,M[];
pair A,B,C,D,E;
B:=(0,0); E:=(2.5*u,0); C:=(0.7*u,-0.8*u); A:=(1*u,1.2*u); D:=(1.8*u,-u);
draw D--A--B--C--D--E--A--C;
draw B--E dashed evenly;
label.top(btex $A$ etex, A);
label.llft(btex $B$ etex, B);
label.bot(btex $C$ etex, C);
label.lrt(btex $D$ etex, D);
label.lrt(btex $E$ etex, E);
I:=3/10[A,B];
J:=7/10[A,C];
K:=7/10[A,E];
dotlabel.ulft(btex $I$ etex,I);
%dotlabel.urt(btex $J$ etex,J);
dotlabel.urt(btex $K$ etex,K);
%%%%%%%
%% DEBUT section %%
M1=whatever[I,J]=whatever[C,B];
M2=whatever[I,K]=whatever[B,E];
M3=whatever[M1,M2]=whatever[E,D];
M4=whatever[M1,M2]=whatever[C,D];
%draw C--M1--M2--E dashed evenly scaled 0.5;
draw C--M1--M4 dashed evenly scaled 0.5;
draw M3--M2--E dashed evenly scaled 0.5;
draw M1--J dashed evenly scaled 0.5;
draw M2--K dashed evenly scaled 0.5;
draw I--J--M4 withcolor red;
draw K--M3 withcolor red;
draw K--I withcolor red dashed evenly;
draw M3--M4 withcolor red dashed evenly;
dotlabel.bot(btex $J$ etex,M4);
endfig;
end