10 LET x=RND*200
 20 LET y=RND*173
 30 FOR i=1 TO 20000
 40 LET vertex=INT (RND*3)
 50 IF vertex=1 THEN GO TO 100
 60 IF vertex=2 THEN GO TO 130
 70 LET x=x/2
 80 LET y=y/2
 90 GO TO 150
100 LET x=100+(100-x)/2
110 LET y=173-(173-y)/2
120 GO TO 150
130 LET x=200-(200-x)/2
140 LET y=y/2
150 INK vertex+1
160 PLOT x,y
170 NEXT i
180 INK 0