geom3d

 compute the radius of a given object

Parameters

 obj - geometric object

Description

 • If obj is a sphere, radius(obj) returns the radius of obj.
 • If obj is a regular polyhedron or an archimedean solid, radius(obj) returns the radius of the circum-sphere which passes through all the vertices.
 • If obj is a dual of an archimedean solid, radius(obj) returns the radius of the in-sphere which touches all the faces.
 • The command with(geom3d,radius) allows the use of the abbreviated form of this command.

Examples

 > $\mathrm{with}\left(\mathrm{geom3d}\right):$
 > $\mathrm{sphere}\left(s,{x}^{2}+{y}^{2}+{z}^{2}=2,\left[x,y,z\right]\right)$
 ${s}$ (1)
 > $\mathrm{radius}\left(s\right)$
 $\sqrt{{2}}$ (2)
 > $\mathrm{tetrahedron}\left(t,\mathrm{point}\left(o,0,0,0\right),1\right)$
 ${t}$ (3)
 > $\mathrm{radius}\left(t\right)$
 ${1}$ (4)