| 释义 |
in-sphere Math.|ˈɪnsfɪə(r)|
[f. in-1 b + sphere n.]
A sphere that touches all the faces of a given polyhedron.
1886G. S. Carr Synopsis Pure & Appl. Math. I. ii. 890 (Index), In-sphere of a tetrahedron. 1939H. S. M. Coxeter Ball's Math. Recreations & Ess. (ed. 11) v. 132 With each of these polyhedra we may associate three concentric spheres: one (the ‘circum-sphere’) through all the vertices, one touching all the edges, and one (the ‘in-sphere’) touching all the faces. |