The area of the circle is the primary determinant for all other properties. Formulas Related to Circles. A 1-sphere is a circle of radius r.
A circles radius is always half the length of its diameter.
This is the simplest formula you can use to get the radius. The n-sphere of unit radius centered at the origin is denoted S n and is often referred to as the n-sphere. Circumference of Circle is the distance all the way around the circle. The circumference C of a circle is a measure of the distance around the circle.