Midradius
The Radius of the Midsphere of a Polyhedron, also called the Interradius. For a RegularPolyhedron with Schläfli Symbol 
, the Dual Polyhedron is 
. Denotethe Inradius 
, midradius 
, and Circumradius 
, and let the side length be 
. Then
 |  |  | (1) |
 | |  | (2) |
For Regular Polyhedra and Uniform Polyhedra, the DualPolyhedron has Circumradius
and Inradius 
. Let 
be the Angle subtended bythe Edge of an Archimedean Solid. Then | |  | (3) |
 | |  | (4) |
 | |  | (5) |
so
 | (6) |
and Circumradius gives | |  | |
|  | (7) |
for an Archimedean Solid.
References
Cundy, H. and Rollett, A. Mathematical Models, 3rd ed. Stradbroke, England: Tarquin Pub., pp. 126-127, 1989.
- Helix
- Helly Number
- Helly's Theorem
- Helmholtz Differential Equation
- Helmholtz Differential Equation--Bipolar Coordinates
- Helmholtz Differential Equation--Cartesian Coordinates
- Helmholtz Differential Equation--Circular Cylindrical Coordinates
- Helmholtz Differential Equation--Confocal Ellipsoidal Coordinates
- Helmholtz Differential Equation--Confocal Paraboloidal Coordinates
- Helmholtz Differential Equation--Conical Coordinates
- Helmholtz Differential Equation--Elliptic Cylindrical Coordinates
- Helmholtz Differential Equation--Oblate Spheroidal Coordinates
- Helmholtz Differential Equation--Parabolic Coordinates
- Helmholtz Differential Equation--Parabolic Cylindrical Coordinates
- Helmholtz Differential Equation Polar Coordinates
- Helmholtz Differential Equation--Prolate Spheroidal Coordinates
- Helmholtz Differential Equation--Spherical Coordinates
- Helmholtz Differential Equation--Spherical Surface
- Helmholtz Differential Equation--Toroidal Coordinates
- Helmholtz's Theorem
- Helson-Szegö Measure
- Hemicylindrical Function
- Hemisphere
- Hemispherical Function
- Hempel's Paradox