1, master the drawing method of vertical lines, and be able to use the drawing method flexibly.

2. Understand the nature of the vertical line.

3. Pay attention to divergent thinking training and stimulate interest in mathematics.

The drawing of vertical line is located in the parallelogram and trapezoid in the second class of Unit 4, Grade 4, primary school mathematics, and it is the origin of drawing regular plane graphics. It will directly affect the drawing and calculation of regular plane graphics. Therefore, it plays a particularly important role in the plane graphics mathematics of the whole primary school, and will also affect students' interest in learning plane geometry.

Prepare:

1, teaching AIDS: courseware, a set of mathematical trigonometry, and a list of questions.

2. School tools: students use a set of triangular rulers.

Guide students to summarize the method of drawing a vertical line through three links: try to draw a vertical line by yourself-comparison method-courseware demonstration. That is:

(1) Hold the hypotenuse, so that a right-angled edge of the triangular ruler coincides with the straight line.

(2) With the cooperation of both hands, translate the triangular ruler along a straight line, so that the other right angle edge is close to the designated point.

③ Draw a straight line along another right angle.

After students have mastered the drawing method of vertical lines, let them draw vertical lines through dots on a straight line to consolidate the correct drawing method. At the same time, the teacher emphasized the trilogy of "coincidence, translation and line drawing".