Dhristi JEE 2022-24

What is Ruler?

Are you someone who looks at a ruler but doesn't understand how to use it? or do you ever wonder why so many different types of rulers are used? Why can’t just one ruler of 15 cm be sufficient? Vedantu will answer all these questions below. In this article, you will learn what is a ruler, its type, reading a ruler, and its uses.  

Ruler Meaning in Maths - A ruler is a device or tool that is used in geometry and technical drawing, as well as engineering and construction technologies to measure the distance of a straight line. A math ruler is used to measure the length in both metric and customary units. The rulers are marked with standard distance in centimetres in the top and inches in the bottom and the intervals in the ruler are called hash marks.

Types of Ruler

There are different types of ruler depending on the material it is made of. Rulers are made from wooden, plastics and metal. Plastics are used to make rulers since they were invented as they could be moulded with length markings. Material rulers are used at a mechanical workshop. Sometimes a metal edge is embedded into a wooden desk ruler to preserve the edge when used for straight-line cutting.

Depending on the size of the ruler there are two types of ruler - a short ruler and a long ruler. Short rulers are 15 centimetres which are very convenient to carry and long rulers are 30 centimetres or 12 inches long, it is useful to draw larger drawings.

Line Gauge - This ruler is used in the paint industry and is made from a variety of materials, typically metal or clear plastics. The basic unit of measurement in the basic line gauge includes inches, agate, picas, and points.

Measuring Instruments - This instrument is made similar to the ruler function and they are portable by folding or retracting into a coil as in metal tape measure. When they are extended to use, It is straight as a ruler. For example, you can take a carpenter's ruler which is 2 m long and when it is folded, it's just 25 cm long, so that it can easily fit into the pocket.

Flexible Length Measuring Length - This instrument does not need to be straight, it is used by tailors to measure the fabric. The length of the tape is calibrated by inches and centimetres. It is used by a tailor to measure the solid body length, for example, a person's body. As well as linear length measurement, for example, a person's leg.

A Contraction Ruler - In this ruler there are larger divisions compared to the standard division, to allow the shrinkage of the metal casting. The contraction ruler is also known as the shrinkage or shrink ruler.

Screen Rulers - It is a type of ruler software programme, where you can have a digital scale on the screen by setting up the pixel. They are functional in both mobiles and the computer and it is useful in the absence of a physical ruler.

Measuring Objects Length using Ruler

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To measure the length of any object, primarily place the first hash mark (which is at Zero marking) of the ruler, exactly at one end of the object. Then set the object along the ruler and then finally note down the final hash marks, which is the endpoint of the object. Refer to the above diagram for a better understanding of the process.

Reading Ruler

Ruler Measurements in Centimetre - A ruler will be having centimetre and millimetre markings. A centimetre is smaller compared to an inch. The hash marks with numbers on the upper side represent the centimetre. The millimetre is smaller than the centimetre, the smaller hash in between centimetres is known as a millimetre.

10 millimetres is equal to 1 centimetre.

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1/10 = One-tenth of the cm.

3/10 =  Three tenth of cm.

5/10 =  Five tenth of cm.

8/10 =  Eight tenth of cm.

1 is equal to 1cm.

Ruler Measurements in Inches - Inch is bigger than the centimetre. The big long hash with numbers opposite to the centimetre is known as the inches. There are a total of 16 sub hashes between the marking of one inch on the ruler.

Uses of a Ruler

After going through what is the ruler? We understood that ruler in maths is used to measure a line and the straight edges, which allows them to be used for drawing, scoring, and cutting. Many times they are also used in engineering, carpentry and the print fields.

Uses of Rulers in Geometry

In geometry, a ruler without having any marks on them could be used for drawing only a straight line between two points. It is also used to draw graphs and tables due to its straight edge.

It is used in the ruler and compass construction, where an unmarked ruler and compass can be used for construction. It is also useful in bisecting the angle by using an unmarked ruler and compass.

Do You know?

Which is the largest preserved ruler? Copper alloy rod is the oldest preserved ruler from c. 2650 BCE and it was by the German Assyriologist Eckhard Unger while excavating at Nippur.


A ruler is a tool that you will be encountering multiple times in your academic life. Each time it will come across in a different format and different least count, but the basic way of reading will remain the same.

After reading this article we have become aware of the importance of a ruler, its type and how it is read. Ruler is the most basic tool of geometry and also the most important one because only after learning to read it, you can proceed towards using other tools. 

FAQs on Ruler

1. How will the topic of ruler - types, measuring objects length, reading, uses, and faqs benefit me?

The topic of Ruler has long-standing applications. You will be using rulers of different measurements for various purposes. You will be using them in mathematics for constructing diagrams, in other subjects for drawing figures. To measure the length of anything in practical life. It will also help you in understanding other measuring tools such as a protractor, set square, etc. Rulers will also help you get acquainted with various units of measuring distance. You need to practise a few times to get a grasp over its application.  

2. How can I download ruler?

Unfortunately you cannot download Ruler from Vedantu’s website. Because the information on this topic is not available in the form of a pdf, rather it is made available to you for free in the form of free web content. You read it without downloading or signing in. You can access the same information from Vedantu’s mobile application. This ensures that no extra load is put on the storage of your device. Also, all of it is available for free. You can read it umpteen times for the sake of revision. 

3. I want to complete studying the topic of ruler in one night is it possible?

Yes it is very much possible for you to complete studying Ruler. Because it is a very easy concept that can be understood by young learners. But to be able to construct the measurements mentioned in the questions at one go, you need a lot of practice. And practice takes time and patience. We suggest you finish the theory part of it as soon as possible and without wasting any time, jump towards solving questions mentioned in the geometry section of your syllabus. 

4. How relevant is ruler in the future?

Relevance of Ruler remains unquestionable. If you are someone who is having access to education you are bound to come across rulers at various points during years of schooling. You will be using a ruler at many places - in maths, for drawing figures in chemistry, physics, biology, etc. Even for constructing advanced level constructions in geometry, you will be needing rulers. You will be using longer rulers in higher standards when you will study civil engineering or architecture. You should practice this and other topics in geometry thoroughly to prepare for future studies as well as for the upcoming exams.

5. Why should I study ruler from vedantu?

Vedantu provides the best study materials for geometry in the market. All the study materials are prepared by trustworthy subject matter experts. They designed these while keeping the convenience of students in mind. The same care has been taken while preparing Ruler. Vedantu has tried to explain this topic with pictures so that it becomes for you to relate it with an actual ruler. Also, Ruler is available for free on the website. You can also cover the topic of Geometric Tools from Vedantu’s website, this will conclude the topic entirely.

6. How wide is an inch?

One inch (2.5 cm) is roughly equal to the measurement from the top knuckle on your thumb to your thumb tip. Measure and compare with one inch to check the difference between them. You can use your hand as a measuring guide for measuring items under 6 inches (15 cm).

7. Can we measure with our phone?

Yes, we can measure with our phones. By launching the measure application, then point the phone's camera at the object you want to measure. Then pick two points you want to measure the distance between them, the virtual tape measures either the height or length of the object. But always remember that the measurement done through the phone application is not always accurate.