% --- start of displayed preamble in the book ---
input geometriesyr16
% --- end of displayed preamble in the book ---
defaultfont:="ptmr8r";
warningcheck:=0;
beginfig(1)
figuremainlevee(0,0,5u,5u);
trace grille(1) withcolor gris;
origine((3,2));
trace axes;
pair A,B,C;
A=placepoint(-2,-1);
B=placepoint(1,-1); C=placepoint(1,2);
trace polygone(A,B,C) withcolor rouge;
trace cercles(A,B,C) withcolor bleu;
nomme.llft(A); nomme.lrt(B);
nomme.top(C);
finmainlevee;
endfig;
end;