(a) 0 0 100 100 makesymbol  (b) 0 0 50 50 makesymbol  (a)open 1 0 0 50 100 makegeometry 2 80 80 90 90 makegeometry 3 70 70 80 80 makegeometry (Top)open (a) 0 0 makeinstance (b) 75 75 makeinstance  (a) 300 200 makeinstance (b) 375 275 makeinstance 4 60 60 110 110 makegeometry