1. Draw a beautiful drawing board as the base of handwritten newspaper. Then, in the middle of the neat white paper, write the topic "the measurement of the fourth grade angle"
2. Draw a butterfly in the upper left corner to make the content full and vivid.
Draw a beautiful campanula in the upper left corner as an ornament.
4. On the left side near the middle, the relevant content of the fourth grade corner is increased in a large area, so as to enrich the picture and enrich the content.
5. Draw a little girl in the lower right corner to make the content full and vivid.
6. Draw a text box in the blank position, add the corresponding text content in the text box, and the handwritten newspaper will be ready.
The measurement of angle includes: line segment, straight line and ray; Classification of angles; Angle measurement and drawing. Students encounter difficulties in learning line segments, straight lines, rays and measuring angles with protractors.
First, the center of the protractor coincides with the vertex of the angle, and the zero scale line coincides with one side of the angle.
Secondly, the scale on the protractor on the other side of the angle is the angle of this angle. Moreover, the degrees on the protractor are divided into inner circle scale and outer circle scale, and the reading results are different at different angles.
The key content of angle measurement in this chapter is nothing more than learning to measure angles with a protractor. And how to draw a given angle with a protractor. In addition, in addition to the protractor, you should learn to draw special angles with the degrees on the triangle ruler, such as 30 degrees, 45 degrees, 60 degrees, 90 degrees, 150 degrees, 15 degrees. 135 degrees, 120 degrees, etc.
In this chapter, students should master the knowledge of linear ray angle and further study space and graphics. Master and understand the measurement method of angle. So as to cultivate students' practical ability.
1, line, ray, line segment
Straight line: it can extend to both ends infinitely, and has no end points.
Ray: It can extend infinitely to one end and has only one endpoint.
Line segment: cannot be extended and has two endpoints. A line segment is a part of a straight line.
2. What are the connections and differences between straight lines, rays and line segments?
(1), straight lines and rays can extend indefinitely, so the length cannot be measured.
② The length of the line segment can be measured.
③ A line segment has two endpoints, a straight line has no endpoint, and a ray has only one endpoint.