Given the teaching of geometry in the mathematics major in  secondary school level, while teaching chapter 1 with the subject of Circle (Lesson 3 of the inscribed and circum Polygons), we find that there are several specific and important points that motivated me to do more research on them. Interestingly, while reading about the above mentioned topics, I found that some of these points have a wonderful relationship with each other. Like the center of the circumcircle that intersects with the point of intersection of the altitudes and the center of gravity of the triangle (Euler theorem) or several other points that all lie on another circle (the nine-point theorem) or the distance between the centers of the inscribed and circum circles and many other things