Question 2: Is the four-point circle knowledge in senior high school? Is it difficult? 5 points Jiangsu students said that this is the knowledge of the second day.

Question 3: What does "four-point * * * circle" mean in mathematics? For three points on a plane that are not on the same straight line, there must be a circle to make these three points on the circumference, so the "three-point * * * circle" is meaningless.

And "four-point * * * circle" means that for four points, there is a circle that makes all four points on the circumference. Any four points do not meet this condition.

"Four-point * * * circle" has three properties: (1) The vertex angles of two triangles connected by four points of * * * circle are equal; (2) Diagonal complementation of quadrilateral inscribed in a circle; (3) The outer angle of a quadrilateral inscribed with a circle is equal to the inner diagonal.

Question 4: The nature of the four-point circle is a compulsory chapter in senior high school of Beijing Normal University. What chapter did I learn in junior high school? I was in my third year. Note: Primary school lasts for 6 years and junior high school lasts for 3 years. . .

Question 5: Math, how to use a four-point circle? Thank you for your 30 points.

Question 6: "Four-point * * * circle" is the content of junior high school mathematics, or is the four-point * * * circle of senior high school the content of junior high school mathematics?