1, the construction mode of mind map is to determine a central theme, lead out sub-themes, and then divide the sub-themes into levels to draw a mind map.

2. Use the simplest language to determine the mathematical theme to be drawn. Take the measurement of angle as an example.

3. An angle is a figure composed of two rays drawn from a point. Get to know the rays first.

4. Draw line segments and straight lines with rays and compare their similarities and differences.

5. Let's mark the key words on the mind map with important knowledge points about angles.

6. In this mind map, the definition of light is derived from angle. You can draw a relationship line between angle and light to connect knowledge points in series.