beginfig(1); u = 0.1000000000 cm; draw ( 0.0000000000u, 0.0000000000u)-- ( 100.0000000000u, 0.0000000000u)-- ( 100.0000000000u, 80.0000000000u)-- ( 0.0000000000u, 80.0000000000u)--cycle; draw fullcircle xscaled 38.0000000000u yscaled 38.0000000000u shifted ( 19.0000000000u, 61.0000000000u); draw fullcircle xscaled 38.0000000000u yscaled 38.0000000000u shifted ( 81.0000000000u, 61.0000000000u); draw fullcircle xscaled 38.0000000000u yscaled 38.0000000000u shifted ( 81.0000000000u, 19.0000000000u); draw fullcircle xscaled 38.0000000000u yscaled 38.0000000000u shifted ( 19.0000000000u, 19.0000000000u); endfig; end;