ENGINEERs MEASURE TO CARPENTERs MEASURE
Some construction drawings have dimensions in engineers measurements
instead of carpenters measurements. Engineers measurements are based on feet
and decimal parts of a foot, where as Carpenters measure is based on feet, inches,
and fractions of an inch. You must know how to convert an engineers measure to
a carpenters measure. For example, using the carpenters rule (3-4-5) many times
your calculation will be in engineers measure such as the diagonal of a right triangle
being 12.65', and you can not find 12.65' on your tape measure, so you must convert
this to inches and fractions of an inch (1/32, 1/16, 1/8, 1/4). As Builders we try
and convert all dimensions to the nearest sixteenth of an inch.
Convert 12.65' to feet, inches, and sixteenths of an inch.
You already know that feet a is given (12') now, you need to convert the decimal
part of a foot (.65') into inches and sixteenths of an inch by multiplying .65' by 12''.
Now, you have converted the .65' to inches which is (7'') with a remainder of
.80''. Next, convert .80'' to sixteenths of an inch by multiplying .80 x 16.
Now that you have converted .80'' to sixteenths of an inch which is (12.80/16),
you can not leave this equation like it is without rounding off. In this example you
must round up to (13). So the answer to this calculation is:
Answer: 12'7 13/16''
Angles are of four types:
Right anglea 90° angle.
Acute anglean angle less than 90°.
Obtuse anglean angle greater than 90°, but less than 180°.
Reflex anglean angle greater than 180°.
All areas are measured in squares.
The area of a square is the product of two of its sides and since both sides are
equal, it may be said to be the square of its side.
NOTE: The area of any plane surface is the measure of the number of squares
contained in the object. The unit of measurement is the square of the unit which
measures the sides of the square.