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

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)