100 DECLARE EXTERNAL SUB circle
120 SET WINDOW -4,4,-4,4
130 CALL circle(1,-1,2)
140 END
200 EXTERNAL SUB circle(a,b,r)
210 OPTION ANGLE DEGREES
220 FOR t=0 TO 360
230    PLOT LINES: a+r*COS(t),b+r*SIN(t);
240 NEXT t
250 END SUB  
     
     
