I recently listened to an open class entitled "1 1.4" in the textbook Mathematics (Part VIII) published by Su Ke. In class, the teacher puts forward a set of propositions to the students and asks them to say the inverse propositions of these propositions. One of the propositions is that "all four corners of a square are right angles" mentioned in the title of this paper. After a little meditation, some students replied that the inverse proposition of this proposition is "right angles are the four corners of a square" Because the students' answers were not what the teacher expected, the lecturer went to the blackboard and drew a square, and wrote down the above propositions in the form of "known" and "verified". Finally, he came to the correct conclusion that "if all four corners of a quadrilateral are right angles, then this quadrilateral is a square" (which is also the standard answer in teaching reference). Quite a few students are still blind, which can be said that the speaker is in a fog and the listener is in a daze. Students are like this. What do teachers think of this problem? After talking with some teachers, I learned that quite a few teachers are also confused. What's wrong with the students' answers? How should teachers analyze and generate the inverse proposition of a proposition in classroom teaching? Teachers generally find this part difficult to teach and learn. In fact, to solve these problems, we have to start from the proposition itself! Nowadays, middle school textbooks generally use "judgment" to directly define propositions. Therefore, to study propositions and their inverse propositions, we must study "judgment". This paper intends to start with "judgment" and then study the proposition and its inverse proposition in order to praise it. (This article has 3 pages) [Continue reading this article]