Radius
The distance from the center of a Circle to its Perimeter, or from the center of a Sphereto its surface. The radius is equal to half the Diameter.
See also Bertrand's Problem, Circle, Circumference, Diameter, Extent, Inversion Radius,Kinney's Set, Pi, Radius of Convergence, Radius of Curvature, Radius (Graph), Radiusof Gyration, Radius of Torsion, Radius Vector, Sphere- Ring Cyclide
- Ring Function
- Ringoid
- Ring Torus
- Risch Algorithm
- Rising Factorial
- Rivest-Shamir-Adleman Number
- RMS
- r(n)
- Robbin Constant
- Robbins Algebra
- Robbins Equation
- Robbin's Inequality
- Robertson Condition
- Robertson Conjecture
- Robertson-Seymour Theorem
- Robin Boundary Conditions
- Robin's Constant
- Robinson Projection
- Robust Estimation
- Rodrigues Formula
- Rodrigues's Curvature Formula
- Rogers-Ramanujan Continued Fraction
- Rogers-Ramanujan Identities
- Rolle's Theorem