What is the difference between a ruler and a rule?

What is the difference between a ruler and a rule?

As nouns the difference between ruler and rule is that ruler is a (usually rigid), flat, rectangular measuring or drawing device with graduations in units of measurement; a rule; a straightedge with markings; a measure while rule is a regulation, law, guideline.

What is a straightedge used for?

A straightedge or straight edge is a tool used for drawing straight lines, or checking their straightness. If it has equally spaced markings along its length, it is usually called a ruler.

Is a ruler straight?

A ruler is an instrument that can be used for measuring distances or to draw straight lines in printing, geometry, technical drawing and many other things. Throughout the history, humans usually take their parts of the body as measuring units.

What are straight edges made from?

Straight edges are used to check if a surface is flat and straight. This one from Preisser is made of a special, hardened, steel alloy, and tapers to a point at one end.