👉 Circumscriptions, or circumferences, are a type of geometric shape that is formed by connecting two radii at each end of a circle. They can be used to measure the circumference of many objects, including circles and other shapes. In geometry, a circumcircle is any circle that touches all points on its circumference exactly once. The radius of this circle is called the circumradius of the circumcircle, and it is related to the diameter by the formula: \[ r = \frac{