Every student knows what a protractor is. This seemingly unsightly tool performs very important functions not only in mathematics lessons. We will tell about what it is, as well as how to use it correctly.
What is a protractor?
A protractor is an object with the help of which each of us can not only measure angles, but also build them. Outwardly, it resembles a semicircular ruler with a scale and divisions. At the bottom, on a flat surface, we’ll find the usual straight ruler for measuring segments. In the upper part there is a semicircle with a double scale for measurements. In each of the directions, the scale is dispersed along the transporter from 0 to 180 degrees.
Terms of use
The school explains what a protractor is in math classes. It is here that there is a need for measurements.
In order for us to know what one degree is, we need to divide the circle into 360 equal parts. One of these parts will be equal to 1 degree. The size of the circle does not affect the degree! This is easy to verify.
Draw two circles of different diameters and divide each into 360 equal parts. Then we impose a smaller circle on a large one and see that the lines coincide.
Measure the angle
A protractor helps build and measure the angle. A degree is a common unit used to measure angles. There are several varieties of angles:
- Acute. This is called an angle of up to 90 degrees.
- A straight angle is 90 degrees.
- The obtuse angle ranges from 90 to 180 degrees.
- The expanded angle is a straight line or 180 degrees.
- The full angle looks like a circle and is 360 degrees.
It’s easy to figure out how to measure the angle. In order to find out what the angle is, we need to set the protractor so that its center is located at the top of the corner, and the straight side coincides with one of its sides. The scale will show us the number of degrees of a given angle. In such a simple way, we can find out what kind of corner is in front of us.
To build an angle with a given degree, you should attach the straight part of the protractor to the line, and its center to the beginning of the line. Subsequently, this point will be the top of the corner. Then on the scale we look for a given number and put a point. Now the protractor can be removed and connected by a segment to the beginning of the line (the top of the corner) with the marked point.
School stationery produced by different companies differ in material, color, size. So: for those whose protractor turned out to be longer than the length of the corner, and it is not possible to determine its value, the side of the corner must be extended using a straight ruler.
Schoolboy set
For good reason, junior students are not familiar with the protractor. When applying it, a certain knowledge base should be laid. To fully work with him in the lesson, children study a number of related subjects. Before learning what a protractor is, schoolchildren must perfectly master the straight ruler, draw straight lines, study addition and subtraction, master the compass, know the geometric shapes, and so on. This whole process takes time, and only after graduating from elementary school, the student can add a protractor to his toolbox.
Students are now offered school supplies in a huge selection. Protractor is no exception. Manufacturers are trying to cater to the most demanding customer needs. Tools are made in various colors. Bright colors are always liked by children. Sometimes even in the same class one cannot find the same transportation, which makes it easier to find them when they are lost. Everyone chooses shapes and sizes to their 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 opaque, is more practical in that the scale is not erased, and this allows it to be used much longer in action, accurately determining angles.
The protractor is not as demanded by schoolchildren as the ruler, but it accompanies students until the final exam. Some of the graduates of the school choose specialties that are related to measuring and constructing angles, designing buildings and structures, working with drawings. Because of their professions, they constantly have to deal with protractors and its derivatives. But the former classmates of the 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.
Total
Today, modern children are used to extracting any information from the Internet. However, it does not help in measuring angles. Only the ability to use the protractor will make it possible to correctly determine them. This will undoubtedly be useful to future engineers and designers in work, and every educated person should have the skills to work with protractors, so everyone should be able to use such a tool!