When measuring the angle, first put the protractor on the top of the angle, then find the vertex of the angle, make the center of the protractor coincide with the vertex of the angle, and then make the side of the angle coincide with the zero scale line. After completing the two coincidences, we can measure the degree of the angle. Find the other side of the angle and see which scale of the protractor the other side of the angle falls on. At this time, the angle degree is how much.

As the name implies, it is an instrument used to measure the degree of angle, which can measure angle, inclination, verticality and levelness. In addition, the protractor is also a drawing tool, which can draw angles, vertical lines and parallel lines. It can be used as an internal and external right-angle ruler to open and close. It can also be used as a long and short ruler to read accurately and intuitively, and draw a circular dimension of the specified size. The protractor is usually made of plastic or iron and is often used with a compass.