The use method of protractor is as follows (this method can be used with or without inner and outer rings):

1, let's look at the structure of the protractor. A protractor is a tool for measuring angles, which is generally semicircular.

2. The diameter of the semicircle is the zero scale line of the protractor, and the center of the diameter is the center of the protractor.

3. The scale on the semicircle is used to measure the degree of angle, ranging from 0 to 180 degrees.

4. Let's take a look at the usage. When measuring the angle, first put the protractor on the drawn angle, and then find the vertex of the angle, so that the center position of the protractor coincides with the vertex of the angle.

5. Overlap one side of the angle with the zero scale line. When the two overlaps are completed, find the other side of the angle and see which scale the other side of the angle falls on. What is the number of horns at this time?

Extended data:

Using formula of protractor

1, click this point, and the center of the protractor coincides with the vertex of the angle.

2. Connect the edges so that the 0 scale line of the protractor coincides with one side of the corner.

3. Count and read the scale on the protractor on the other side of the angle, which is the degree of this angle.