What is Linear Measurement?
The linear measurement is the distance between the two given points or objects. Thus, we can define length as:
“Total gap measured between the leftmost and rightmost end of an object in the mentioned system of units.”
Measuring the length of a banana using tape. The length approximates to 5 inches.
Similarly, “height” is the linear measurement between the top and bottom of an object. For example, the height of the cone and a ladder as shown in the image.
The height of the object is the distance between the top and the bottom.
The basic tools used for linear measurement are:
 Ruler – The standard rulers generally measure 15 and 30 cm with markings in mm, cm on top and inches on the bottom.
Standard ruler with measurement markings in millimeter (mm), centimeter (cm) on top and inches on bottom.
 Measuring tape – The measuring tape is more commonly used to measure longer objects such as walls, pieces of fabric and tiles. A measuring tape has metric markings and U.S. customary markings.
Pocket measuring tape with a metal strip and foldable measuring tape.
The markings on the tape and ruler are in the metric and customary system. The next section lists the different units of measurement for length and height.
Units of Linear Measurement
U.S. Customary Units 
International System / Metric Units 
Inches – in Foot – ft Yards – yd Miles – mile 
Millimeters – mm Centimeters – cm Meters  m Kilometers – km 
Using instruments like a ruler and tape, children can measure surrounding objects such as pencil, shoe, a remote, toy car, and spoon. The example below illustrates the placement of a ruler against a screwdriver to measure its length.
To measure the length, place the object and ruler with the tip at the “0”. Mark the number at the end of the object to measure the total length.
Measuring an object using a ruler.
Application
The concept of measurement is the primary step towards quantitative analysis. Kids learn to gather the numbers in terms of measurable quantities such as length, breadth, and height. The knowledge of physical dimensions of objects is used in learning geometry, drawing scalable maps, architecture, and estimating unknown quantities for shapes with the help of formulas.
Fun Facts

Related Math Vocabulary

Length

Tools of linear measurement

Imperial Metrics

SI Metrics

Unit conversion