In set theory, let A and B be two sets. The set composed of all elements belonging to set A and set B is called the intersection of set A and set B, and it is marked as A ∩ B. As an auxiliary tool for learning mathematics, the geometric sketchpad can also be used to demonstrate the intersection of sets. For example, the following figure is a courseware that demonstrates the intersection of sets. In this courseware, we can demonstrate the intersection of set A and set B by clicking the "intersection" operation button, and the common parts of the two groups are indicated by shadows; Click the "Back" operation button to demonstrate the separation of set A and set B, and display two independent sets. In the return state, moving the position of the circle representing set A to the right and right can change the size of the shadow representing the intersection, thus controlling the degree of their intersection.