Extended data:

To calculate the volume of a rotating body:

1. Establish coordinate system, and construct rotation surface and rotation axis;

2. Observing the position of the rotating surface, the common rotating surfaces are curved triangle and curved trapezoid;

3. Look at the position of the rotating shaft in the topic: the rotating shaft is generally the coordinate axis;

4. Find out the curve equation of the revolving surface from the problem;

5. Find the area equation of a single cross-section circle, definite integral and volume.