On a miter saw, when you're cutting a 90 degree cut, the miter saw reads zero. On a protractor, it reads 90. So it's an unending source of confusion for people. RON HAZELTON: So Mark, show me how it works.
A ruler is used to measure units of length, inches, feet and yards. Standard rulers have inches on one side and centimeters on the other. A typical ruler measures up to 12 inches, and is equivalent to 30.48 centimeters. This is also equivalent to 1 foot. Each inch on a ruler has markings in between that are a fraction of an inch.
For items that are not circular, such as sculptures, measure the Height, Width, and Depth of the object. 1  Adjust your ruler so that it is aligned with your object. The ruler should be straight and parallel to the object.  Move to the opposite side of the object you are measuring and read the ruler.