Introduction to Measuring Length

Overview

**Length** : The distance-span between two points is the length. It is measured in meter or in one of its other forms.
Length is specified as a number in reference to the reference-prototype-standard meter (or in one of other derived or similar forms).

distance-span

Length is "the measurement of distance-span between two points, specified in reference to the standard meter"

The word "span" means: full extent or full spread of something.

Length of an object is the distance-span of the object from one end to the other end. To specify the distance-span the standard-unit meter is defined. The figure illustrates reference $1m$ at the top-right corner and the length of line segment $\overline{AB}$ is measured as $3m$ in reference to the standard-unit.

The standard unit of measure for length is "meter"

large or small

The distance between two cities is $200000$ meter. It is noted that the number is very large in some applications.

To simplify specifying such large values, a larger measure of length is defined such as $1$ kilometer = $1000$ meter. Using the larger measure, the distance between two cities is given as $200$ kilometer.

The length of a pen is very small to measure in $1$ meter. It is noted that the number is very small in some applications.

To simplify specifying such small values, a smaller measure of length is defined such as $1$ meter = $100$ centimeter. Using the smaller measure, the length of a pen is given as $7$ centimeter.

The basic unit "meter" is converted into smaller or larger units of lengths.

$1000$ millimeter = *$1$ meter*

$100$ centimeter = *$1$ meter*

$10$ decimeter = *$1$ meter*

$1$ decameter = *$10$ meter*

$1$ hectometer = *$100$ meter*

$1$ kilometer = *$1000$ meter*
* Remember the following:
"milli" is from a Latin root word meaning thousand
"centi" is from a Latin root word meaning hundred
"deci" is from a Latin root word meaning tenth
"deca" is from a Greek root word meaning ten
"hecto" is from a Greek root word meaning hundred
"kilo" is from a Greek root word meaning thousand
*

Among these, millimeter, centimeter, meter, and kilometer are widely used depending on the scale of the length measurement.

what it means

The statement "length of the stick is $3$ meter"

specifies that

"The distance-span of the stick equals $3$ distance-spans given by the standard unit meter".

summary

**Length** : The distance-span between two points is the length. It is measured in meter or in one of its other forms.
Length is specified as a number in reference to the reference-prototype-standard meter (or in one of other derived or similar forms).

Outline

The outline of material to learn "Mensuration basics : Length, Area, & Volume" is as follows.

Note: * click here for detailed outline of Mensuration (Basics). *

• ** Measuring Basics**

→ __Introduction to Standards__

→ __Measuring Length__

→ __Accurate & Approximate Meaures__

→ __Measuring Area__

→ __Measuring Volume__

→ __Conversion between Units of Measure__

• ** 2D shapes**

→ __Perimeter of Polygons__

→ __Area of Square & rectangle__

→ __Area of Triangle__

→ __Area of Polygons__

→ __Perimeter and area of a Circle__

→ __Perimeter & Area of Quadrilaterals__

• ** 3D shapes**

→ __Surface Area of Cube, Cuboid, Cylinder__

→ __Volume of Cube, Cuboid, Cylinder__