3 Sided Polygon

3 Sided Polygon Rafter Table ( 3 - gon )

central angle = 120°
working angle = 60°
plan angle = 30°
miter angle = 20.78 & 12 (60.00°)
hip run per foot = 24.00
apothem multiplier = 2.00000
side wall multiplier = 3.46410

Pitch	Roof Angles		Frieze Block Angles		Hip Rafters					Jack Rafters
Pitch	Roof Pitch Angle	Hip Pitch Angle	Angle	Saw Bevel	Side Cut Angle	Backing Angle	Hip Drop 2x	Hip Drop 4x	Length Per-FT	Side Cut Angle	First 12” O.C.	First 16” O.C.	First 24” O.C.	Spaced 12” O.C.	Spaced 16” O.C.	Spaced 24” O.C.	Multiplier
0	0.00	0.00	0	60	60.00	0.00	0.00	0.00	24.00	60	6.93	9.24	13.86	6.93	9.24	13.86	0.57735
1	4.76	2.39	8.19	59.66	59.98	4.12	0.05	0.13	24.02	59.91	6.95	9.27	13.90	6.95	9.27	13.90	0.57935
2	9.46	4.76	15.89	58.68	59.91	8.19	0.11	0.25	24.08	59.66	7.02	9.37	14.05	7.02	9.37	14.05	0.58531
3	14.04	7.13	22.79	57.16	59.81	12.12	0.16	0.38	24.19	59.24	7.14	9.52	14.28	7.14	9.52	14.28	0.59512
4	18.43	9.46	28.71	55.24	59.66	15.89	0.22	0.51	24.33	58.68	7.30	9.74	14.61	7.30	9.74	14.61	0.60858
5	22.62	11.77	33.67	53.07	59.47	19.46	0.27	0.63	24.52	57.98	7.51	10.01	15.01	7.51	10.01	15.01	0.62546
6	26.57	14.04	37.76	50.77	59.24	22.79	0.32	0.76	24.74	57.16	7.75	10.33	15.49	7.75	10.33	15.49	0.64550
7	30.26	16.26	41.11	48.42	58.98	25.87	0.38	0.88	25.00	56.24	8.02	10.69	16.04	8.02	10.69	16.04	0.66840
8	33.69	18.43	43.85	46.10	58.68	28.71	0.43	1.01	25.30	55.24	8.33	11.10	16.65	8.33	11.10	16.65	0.69389
9	36.87	20.56	46.10	43.85	58.34	31.31	0.49	1.14	25.63	54.18	8.66	11.55	17.32	8.66	11.55	17.32	0.72169
10	39.81	22.62	47.95	41.71	57.98	33.67	0.54	1.26	26.00	53.07	9.02	12.02	18.04	9.02	12.02	18.04	0.75154
11	42.51	24.62	49.49	39.67	57.58	35.82	0.60	1.39	26.40	51.93	9.40	12.53	18.80	9.40	12.53	18.80	0.78322
12	45.00	26.57	50.77	37.76	57.16	37.76	0.65	1.52	26.83	50.77	9.80	13.06	19.60	9.80	13.06	19.60	0.81650
13	47.29	28.44	51.84	35.97	56.71	39.52	0.70	1.64	27.29	49.60	10.21	13.62	20.43	10.21	13.62	20.43	0.85120
14	49.40	30.26	52.75	34.31	56.24	41.11	0.76	1.77	27.78	48.42	10.65	14.19	21.29	10.65	14.19	21.29	0.88715
15	51.34	32.01	53.52	32.75	55.75	42.55	0.81	1.89	28.30	47.26	11.09	14.79	22.18	11.09	14.79	22.18	0.92421
16	53.13	33.69	54.18	31.31	55.24	43.85	0.87	2.02	28.84	46.10	11.55	15.40	23.09	11.55	15.40	23.09	0.96225
17	54.78	35.31	54.75	29.96	54.72	45.03	0.92	2.15	29.41	44.97	12.01	16.02	24.03	12.01	16.02	24.03	1.00116
18	56.31	36.87	55.24	28.71	54.18	46.10	0.97	2.27	30.00	43.85	12.49	16.65	24.98	12.49	16.65	24.98	1.04083
19	57.72	38.37	55.67	27.55	53.63	47.07	1.03	2.40	30.61	42.77	12.97	17.30	25.95	12.97	17.30	25.95	1.08119
20	59.04	39.81	56.05	26.46	53.07	47.95	1.08	2.53	31.24	41.71	13.47	17.95	26.93	13.47	17.95	26.93	1.12217
21	60.26	41.19	56.38	25.45	52.51	48.76	1.14	2.65	31.89	40.67	13.96	18.62	27.93	13.96	18.62	27.93	1.16369
22	61.39	42.51	56.67	24.50	51.93	49.49	1.19	2.78	32.56	39.67	14.47	19.29	28.94	14.47	19.29	28.94	1.20570
23	62.45	43.78	56.93	23.62	51.35	50.16	1.24	2.90	33.24	38.70	14.98	19.97	29.96	14.98	19.97	29.96	1.24815
24	63.43	45.00	57.16	22.79	50.77	50.77	1.30	3.03	33.94	37.76	15.49	20.66	30.98	15.49	20.66	30.98	1.29099

Framing Square usage Example: 8:12 Pitch
(Rafter Length Per Ft = 14.42) (Hip Rafter Length Per Ft = 25.30)
SS Angle = Speed Square Angle
Saw Angle produces compound Speed Square Angle

Tongue (8.00) Blade (12.00) for Rafter Plumb Cut Angle (SS Angle 33.69)
Tongue (12.00) Blade (8.00) for Rafter Level Cut Angle (SS Angle 56.31)

Tongue (8.00) Blade (24.00) for Hip Rafter Plumb Cut Angle (SS Angle 18.43)
Tongue (24.00) Blade (8.00) for Hip Rafter Level Cut Angle (SS Angle 71.57)

Tongue (41.57) Blade (25.30) for Hip Side Cut Angle (SS Angle 58.68) (Saw Angle 30.00)
Tongue (13.86) Blade (25.30) for Hip Backing Angle (SS Angle 28.71)

Tongue (20.78) Blade (14.42) for Jack Rafter Side Cut Angle (SS Angle 55.24) (Saw Angle 30.00)

Tongue (13.86) Blade (14.42) for Purlin Rafter Plumb Cut Angle (SS Angle 43.85) (Saw Angle 28.71)
Tongue (20.78) Blade (14.42) for Purlin Rafter Cross Cut Angle (SS Angle 55.24)

Tongue (13.86) Blade (14.42) for Roof Sheathing Plumb Cut Angle (SS Angle 43.85) (Saw Angle 28.71)
Tongue (20.78) Blade (14.42) for Roof Sheathing Cross Cut Angle (SS Angle 55.24)

Tongue (8.00) Blade (12.00) for Miter Box Gable Mould Plumb Cut Angle (SS Angle 33.69)
Tongue (8.00) Blade (24.00) for Miter Box 2 Cord Polygon Gable Mould Hip Plumb Cut Angle (SS Angle 18.43)
Tongue (20.78) Blade (12.00) for Miter Box 2 Cord Polygon Gable Mould Hip Cross Cut Angle (SS Angle 60.00) (Saw Angle 60.00)

Tongue (13.86) Blade (14.42) for Frieze Block Plumb Cut Angle (SS Angle 43.85)
Tongue (20.78) Blade (14.42) for Frieze Block Cross Cut Angle (SS Angle 55.24) (Saw Angle 46.10)

Tongue (13.86) Blade (14.42) for Square Cut Fascia Plumb Cut Angle (SS Angle 43.85)
Tongue (20.78) Blade (14.42) for Square Cut Fascia Cross Cut Angle (SS Angle 55.24) (Saw Angle 46.10)

Tongue (8.31) Blade (20.78) for Hip Rafter Square Cut Fascia Plumb Cut Angle (SS Angle 34.70)
Tongue (20.78) Blade (14.42) for Hip Rafter Square Cut Fascia Cross Cut Angle (SS Angle 55.24) (Saw Bevel Angle 46.10)