__maths__>__Mensuration : Length, Area, and Volume__>__Introduction to Measurements__### Introduction to Measuring Length

This topic introduced measuring length as "distance-span". It is an absolute standard and measured in reference to a standard `1` unit.

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Which of the following explains measurement of length?

- the measurement of distance-span between two points, specified in reference to the standard meter
- the measurement of distance-span between two points, specified in reference to the standard meter
- the measurement of surface-span in a closed figure, specified in reference to the surface-span of a square of sides 1 meter

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

Which of the following is a meaning for the word "span"?

- s shaped pan
- full extent or full spread of something
- full extent or full spread of something

The answer is "full extent or full spread of something".

What is the term used to refer "full spread of something"?

- Pronunciation : Say the answer once

Spelling: Write the answer once

The answer is "span".

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 `bar(AB)` is measured as `3m` in reference to the standard-unit.

What is the standard unit of measure for length?

- meter
- meter
- height

The answer is "meter"

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

Which of the following help in simplifying such large values?

- it cannot be simplified
- a larger measure of length is defined such as `1` kilometer = `1000` meter.
- a larger measure of length is defined such as `1` kilometer = `1000` meter.

The answer is "a larger measure of length is defined". 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.

Which of the following help in simplifying such small values?

- it cannot be simplified
- a smaller measure of length is defined such as `1` meter = `100` centimeter.
- a smaller measure of length is defined such as `1` meter = `100` centimeter.

The answer is "a smaller measure of length is defined". 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.

**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).

Which of the following explains the statement "length of the stick is `3` meter"?

- it is just length
- The distance-span of the stick equals `3` distance-spans given by the standard unit "meter"
- The distance-span of the stick equals `3` distance-spans given by the standard unit "meter"

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

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