There are five main types of moving point problems in junior middle school mathematics, namely, special triangle formed by moving point, special quadrangle formed by moving point, area problem formed by moving point, similar triangles formed by moving point and minimum sum of line segments formed by moving point. To solve these problems, we need to take four steps.

1, to determine the location of the moving point, we need to turn the moving point problem into a static state and determine whether it is necessary to discuss it in categories;

2. The coordinates of the fixed point are unknown;

3. Indicate the length of the relevant line segment;

4. Establish an equation or function according to the quantitative relationship of line segments.