1  ; how to use polar coordinates:  
 2  ; use the format @radius^angle in place of specifying X,Y words
 3  
 4  G20 G90
 5  G0 X0 Y0 Z0
 6  
 7  ; drill three bolt holes on a 5" diameter
 8  G0 X2.5 Y0
 9  G81 R.1 Z-0.5 F60
10  ^120
11  ^240
12  
13  G90 @1 ^33
14  ; drill a row of holes 1" apart along a 33 degree feature
15  G91 G81 @1 R.1 Z-0.5 L5
16  
17  G90 G0 X2 Y0
18  ; drill 17 evenly-spaced bolt holes on a 4" diameter
19  G91 G81 ^[360/17] R.1 Z-0.5 L17
20  
21  M2