That would depend on where you live UK or US
G41 and G42 are dependent on the direction you are traveling clockwise or counterclockwise
This should help to explain it :-
O0001 (COMP G41 AND G42)
G21 G40
G91 G28 X0 Y0 Z0
(OUTSIDE CW)
G54 G00 G90 G43 X-19.445 Y35.91 Z25. H3 S2500 M3
G00 Z1.
G01 Z-1. F500.
G01
G41 D23 X-5.303 Y14.697 F800. S2500
G03 X0. Y12.5 R7.5
G02 X10.827 Y-6.248 R12.5
G02 X-10.827 R12.5
G02 X0. Y12.5 R12.5
G03 X5.303 Y14.697 R7.5
G01 G40 X19.445 Y35.91
G00 Z25.
(INSIDE CW)
G00 X46.25 Y3.75
G00 Z1.
G01 Z-1. F500.
G01
G42 D23 X50. Y12.5 F800. S2500
G02 X60.827 Y-6.248 R12.5
G02 X39.173 R12.5
G02 X50. Y12.5 R12.5
G01 G40 X53.75 Y3.75
G00 Z25.
(INSIDE CCW)
G00 X53.75 Y-46.25
G00 Z1.
G01 Z-1. F500.
G01
G41 D23 X50. Y-37.5 F800. S2500
G03 X39.173 Y-56.248 R12.5
G03 X60.827 R12.5
G03 X50. Y-37.5 R12.5
G01 G40 X46.25 Y-46.25
G00 Z25.
(OUTSIDE CCW)
G00 X19.445 Y-14.09
G00 Z1.
G01 Z-1. F500.
G01
G42 D23 X5.303 Y-35.303 F800. S2500
G02 X0. Y-37.5 R7.5
G03 X-10.827 Y-56.248 R12.5
G03 X10.827 R12.5
G03 X0. Y-37.5 R12.5
G02 X-5.303 Y-35.303 R7.5
G01 G40 X-19.445 Y-14.09
G00 Z25.
G91 G28 Y0 Z0
M30