## By Two-Foot Rule

To lay off any angle given in the table, open the rule at the middle until the distance between the inside corners at the knuckle joints (6-inches' mark) is equal to the distance given for that angle under Chord.

 Degrees. Chord. Inches. 5 17/32 10 1 1/32 15 1 9/16 20 2 3/32 25 2 19/32 80 3 3/32 85 3 19/32 40 4 3/32 45 4 19/32
 Degrees. Chord. Inches. 50 5 1/16 55 5 17/32 60 6 65 6 7/16 70 6 7/8 75 7 5/16 80 7 23/32 85 8 3/32 90 8 1/2

To lay off an angle greater than 90°, subtract the angle from 180°; lay out the latter angle, extending one side, so that the greater angle formed will be the one required.

## By Steel Square

To lay off any angle given in the table, set either blade or tongue of the square along the line a 5, marking the 12" point at a. Mark c at a distance from b equal to that given in the table for the required angle, and draw ac; then the angle b a c will be the angle sought, approximately correct.

For example, to find an angle of 30°, the distance 6 c is

 Angle. Degrees. Distance. Inches. 5 1 1/16 10 2 3/32 15 3 7/32 18° 25' 4 (J pitch roof) 20 4 3/8 22 1/2 4 31/32 25 5 19/32 26° 33' 6 (1/4 pitch) 30 6 15/16
 Angle. Degrees. Distance.Inches. 33° 42' (1/2pitch) 8 35 8 13/32 40 10 1/16 45 (1/2 Pitch) 12 50 14 5/16 53° 7' (2/3 Pitch) 16 55 17 1/8 60 20 25/32

## Taking A At The 3" Mark

 65 6 7/16 67 1/2 7 1/4 (Octagon Cut) 70 8 1/4
 75 11 3/16 80 17 Angle 90 abc