1, protractor is a tool used to measure the degree of an angle, 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. 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?
The center of the protractor is aligned with the vertex of the angle. The 0 scale line of the protractor is aligned with one side of the corner. After the two are aligned, the other side of the angle faces the scale line several times, and this angle is several degrees. Look at the scale to distinguish the inner and outer rings.
The purpose of mathematical protractor:
1. Draw angle: The protractor can draw any angle conveniently. Just aim the center of the protractor at the vertex of the angle to be drawn, then find the corresponding scale line on the protractor according to the size of the required angle, and draw both sides of the angle along this line.
2. Angle measurement: The most basic function of protractor is angle measurement. Align the vertex of the angle to be measured with the center of the protractor, align both sides of the angle with the scale line of the protractor, and then determine the degree of the angle according to the position of the scale line.
3. Draw vertical and parallel lines: A protractor can also be used to draw vertical and parallel lines. When drawing a vertical line, align one side of the protractor with a known straight line, and then draw a vertical line along the other side of the protractor. When drawing parallel lines, align one side of the protractor with a known straight line, and then draw parallel lines along the same side of the protractor.
4. Compare the sizes of angles: A protractor can also be used to compare the sizes of two angles. Align the vertices of two angles, and then observe the positions of both sides on the protractor to determine which angle is larger.
5. Calculate the angle: The protractor is also a very useful tool for calculating the angle. For example, a protractor can be used to measure the complementary angle or complementary angle of an angle, so as to calculate the size of the original angle.