Angle at Center and Length of Chord for Spacing off the Circumference of a Circle
Spaces on Circle	Angle at Center, Deg, Min	Length of Chord
3	120	0.866025
4	90	0.707106
5	72	0.587785
6	60	0.500000
7	51,26	0.433883
8	45	0.382683
9	40	0.342020
10	36	0.309017
11	32,44	0.281732
12	30	0.258819
13	27,41	0.239315
14	25,43	0.222520
15	24	0.207911
16	22,30	0.195090
17	21,11	0.183749
18	20	0.173648
19	18,57	0.164594
20	18	0.156434
21	17,9	0.149042
22	16,22	0.142314
23	15,39	0.136166
24	15	0.130526
25	14,24	0.125333
26	13,51	0.120536
27	13,20	0.116092
28	12,51	0.111964
29	12,25	0.108118
30	12	0.104528
31	11,37	0.101168
32	11,15	0.098017
33	10,55	0.095056
34	10,35	0.092268
35	10,17	0.089639
36	10	0.087155
37	9,44	0.084805
38	9,28	0.082579
39	9,14	0.080466
40	9	0.078459
Table is calculated for circles having a diameter = to 1. For other circles, multiply the length given by the circle's diameter.