Can You Define The `tern Ruler`?

Actually the ruler is a tool or instrument that is used to draw straight lines and to measure the distances or lengths. It is used in various fields like; geometry, technical drawing, engineering and architecture etc.

There are different forms of this instrument. It may be in the form of a rod labeled with a scale measures, a tape measure or in various other forms used in different jobs.
If we see the term ruler in the context of geometry, it refers to an instrument to draw straight lines. It is not used here for length measurements so that it is unmarked i.e. there is not any scale printed on it. Therefore, in geometry it is sometimes known as straightedges.

These rulers are marked with different scale units. These units may be metric units, imperial units, English units of measurement etc.In the metric measurements, the rulers are marked with numbers as centimeters, millimeters units. The one unit of a centimeter is equal to the 10 millimeters.  The rulers that have imperial measurements show the units of inches where an inch is equal to the 2.5 centimeters. An inch is divided into 16 equal parts. The imperial measurements are more difficult than metric measurements.