Ruler


 
 
Ruler

:This article is about the drawing instrument. Ruler can also refer to a statesman in charge or ceremonial head of state of a country or minor politically significant principality; for this meaning see Monarch or Lists of incumbents.

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A ruler is an instrument used in geometry and technical drawing to measure short distances and/or to rule straight lines. Strictly speaking, the ruler is the instrument used to rule and calibrated stick for measurement is called a measure. However, common usage is that a ruler is calibrated so that it can measure, creating ambiguity in what a ruler is allowed to do in Ruler-and-compass constructions.

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For instance, a ruler with measurement capability (e.g. its own length) can be used for angle trisection. This is resolved by referring to an instrument that can only rule as a straightedge.

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Practical rulers have distance markings along their edges.

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How these distance markings are applied and calibrated should be described here, including a history of old methods.

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~ Table of Content ~

Introduction
See also
External links
 
FR: Règle


 

~ Related Subjects ~

Angle trisection (1) - Ruler-and-compass constructions (1) - Straightedge (1) - Mechanical work (1) - Tool (1) - Measure (1) - Lists of incumbents (1) - Monarch (1) - Instrument (1) - Technical drawing (1) - Geometry (1) -
 

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