beginfig(1);
    draw fullcircle scaled 42mm;
    fill fullcircle scaled 42mm withcolor .8*white;
    fill fullcircle scaled 4cm withcolor .8*(green+red);

    draw (0, 1cm) withpen pencircle scaled 3bp;
    draw (1cm, 0) withpen pencircle scaled 3bp;
    draw (0, -1cm) withpen pencircle scaled 3bp;
    draw (-1cm, 0) withpen pencircle scaled 3bp;

    draw (-3cm, -3cm)--(3cm, 3cm) dashed evenly;
    draw (-3cm, 3cm)--(3cm, -3cm) dashed evenly;
endfig;

beginfig(2);

		u:=0.0005cm

    draw fullcircle scaled 8488u;
    fill fullcircle scaled 8488u withcolor .8*white;

    draw (-4423u, -5148u) withpen pencircle scaled 3bp;
    draw (-5679u, 4873u) withpen pencircle scaled 3bp;
    draw (-4984u, -5832u) withpen pencircle scaled 3bp;
    draw (6441u, -5527u) withpen pencircle scaled 3bp;

endfig;

beginfig(3);

		u:=0.0001cm

    draw fullcircle scaled 7822969u;
    fill fullcircle scaled 7822969u withcolor .8*white;

    draw (-6143505u, -4843158u) withpen pencircle scaled 3bp;
    draw (5462938u, 4306631u) withpen pencircle scaled 3bp;
    draw (-5810567u, -4580691u) withpen pencircle scaled 3bp;
    draw (-4178014u, 5299777u) withpen pencircle scaled 3bp;

endfig;
end.
