// Ne pas confondre size, length et arclength !
size(7.5cm,0);

path chemin=(-3,1)..(-1,2)..(4,0)..(5,3);

draw(chemin,blue,dot);
label(format("size(chemin) = %i",size(chemin)),truepoint(S),S);
label(format("length(chemin) = %i",length(chemin)),truepoint(S),S);
label(format("arclength(chemin) = %f",arclength(chemin)),truepoint(S),S);

shipout(bbox(3mm,white));