- In any size square shape the length of the diagonal is 1.414 x the length of any side.
- To lay out a 90° corner, measure out 3 ft. on one side and 4 ft. on the other and adjust until the diagonal is exactly 5 ft, or use 6 ft and 8 ft., then 10 ft will be the diagonal.
- Because a rule is laid out in 16ths of an inch, to change a decimal into 16ths multiply that number by 16, (ex. .375 in. x 16 = 6 so .375 = 6/16 or 3/8 in.)
- If a portion of a foot is expressed as a decimal rather than inches, multiply by 12 to find inches (ex. .750 ft. x 12 = 9 in.).
- If you have an open beam ceiling with, for example, a 6 in. wide hip and 5 in. rise, then to figure the amount to drop hip, or amount of chamfer (or bevel) off each edge of hip use this formula:
Rise x thickness of Hip
(ex. 5 in. x 3 in.)
_____________________ = .88 or 7/8 in.