What is protractor? Rules for measuring angles

Every schoolboy knows what a protractor is. This seemingly unsightly instrument performs very important functions not only in the lessons of mathematics. About what he is, and also how to use it properly, we will tell further.

What is protractor?

A transport vehicle is an object through which each of us can not only measure angles, but also build them. Outwardly it resembles a semicircular ruler with a scale and divisions. Below, on a flat surface, is the usual straight line for measuring line segments. In the upper part is a semicircle with a double scale for measurements. In each direction, the scale is dispersed by transport from 0 to 180 degrees.

Terms of use

The school explains what a protractor is, in the lessons of mathematics. It is here that there is a need for measurements.

In order for us to know what one degree is equal to, we need to divide the circle into 360 equal parts. One of these parts will be 1 degree. The magnitude of the circle does not affect the degree in any way! It's easy to check.

Draw two circles of different diameters and divide each into 360 equal parts. Then we will place the smaller circle on the larger circle and see that the lines have coincided.

We measure the angle

The transporter helps to build and measure the angle. Degrees are a common unit used to measure angles. There are several varieties of angles:

• Acute. This is called the angle up to 90 degrees.
• The right angle is 90 degrees.
• The blunt angle varies from 90 to 180 degrees.
• The unfolded angle is a straight line or 180 degrees.
• The full angle looks like a circle and is 360 degrees.

It is not difficult to understand how to measure the angle. In order to know what the angle is, we need to install the protractor in such a way that its center is located at the top of the corner, and the straight side coincides with one of its sides. The scale will tell us the number of degrees of this angle. Here in such a simple way we can find out what the angle is in front of us.

To build an angle with a given degree, you must attach the straight part of the protractor to the line, and its center to the beginning of the line. Later this point will be the vertex of the angle. Then on the scale we find the given number and set the point. Now the protractor can be removed and connected by a segment of the beginning of the line (the corner vertex) with the marked point.

School stationery produced by different companies, differ in material, color, size. So: those who have a protractor more than the length of the angle, and it is not possible to determine its value, the side of the angle should be extended using a straight ruler.

Schoolboy Recruitment

It's not for nothing that junior students are not familiar with the protractor. When using it, a certain knowledge base must be laid. For full-fledged work with him at the lesson, the guys are studying a number of related subjects. Before learning what a protractor is, schoolchildren must perfectly master a straight line, draw straight lines, study addition and subtraction, master compasses, know geometric figures, and so on. This whole process takes time, and only after completing the primary school, the student can add the protractor to his toolbox.

Students are now offered school stationery in a huge choice. The transport worker is no exception. Producers try to please the most demanding customers. The tools are made in different colors. Bright colors always like children. Sometimes even in one class you can not find the same protractors, which makes it easier for them to search for them. The shapes and sizes are chosen according to your taste.

Most of these products are made of plastic, and this significantly reduces its cost. But there are wooden and even iron protractors. As practice shows, metal, although not opaque, is more practical in that the scale is not erased, and this allows much longer to apply it in action, accurately determining the angles.

The transport worker is not so demanded by schoolchildren as a ruler, but he accompanies students up to the final exam. Some of the school's graduates choose specialties that are related to measuring and building angles, designing buildings and structures, working with drawings. Due to their professions, they constantly have to deal with protractors and their derivatives. But former classmates of current engineers, sometimes even with the deepest humanitarian bias, easily remember the skills of handling this subject and determine the number of degrees at any angle.

The result

Today, modern children are used to extract any information from the Internet. However, it does not help in the measurement of angles. Only the ability to use the protractor will enable them to be properly identified. Future engineers and designers are indisputably useful in the work, and every educated person must have the skills to work with protractors, so everyone should be able to use such a tool!