u := 1.25cm;
r := 5pt;

beginfig(1);
for i=0 upto 4:  z[i]=u*dir(90-72*i);  endfor
draw z0--z4--z1--z2--z3--z0--z2;
pickup pencircle scaled r;
for i=0 upto 4:  draw z[i];  endfor
label.top(btex$Z$etex, z0+r*dir90);
label.rt(btex$A$etex, z1+r*dir0);
label.lrt(btex$B$etex, z2+r*dir-30);
label.llft(btex$C$etex, z3+r*dir-150);
label.lft(btex$Y$etex, z4+r*dir180);
endfig;

bye