SET WINDOW -1.2,1.2,-1.2,1.2
DRAW circle
END

EXTERNAL PICTURE circle
OPTION ANGLE DEGREES
SET LINE width 3
LET kaku = 90
FOR x=0 TO kaku
   PLOT LINES:COS(x),SIN(x);
NEXT x
PLOT LINES: 0,0;1,0
PLOT LINES: 0,0;COS(kaku),SIN(kaku);
END PICTURE