caption: The image shows an open book with a drawing of a circle on it. The book is filled with diagrams and text, providing detailed information about the geometry of the circle. The drawing is composed of various shapes and lines, including circles, squares, triangles, and rectangles, all of which are connected by lines and arrows. The colors used in the drawing are mostly shades of blue, green, and yellow, giving the book a vibrant and eye-catching look.