👉 Circumradii are a mathematical concept in geometry used to measure the radius of the circumference of a circle. They are closely related to the area of circles, specifically to the problem of finding the length of an arc of a circle that is subtended by a central angle. The circumradius (R) of a circle with radius \(r\) and center \((x,y)\), where \(y = r\sqrt{1 - x^2}\), can be expressed as: \[