| 释义 |
trihedral, a. (n.) Geom., Cryst., Nat. Hist., etc.|traɪˈhiːdrəl, -ˈhɛdrəl|
Also triedral.
[f. Gr. τρι- tri- + ἕδρα base + -al1.]
Of a solid figure or body: Having three sides or faces (in addition to the base or ends); bounded laterally by three surfaces; triangular in section. trihedral angle or trihedral quoin, a solid angle formed by three surfaces meeting at a point.
1789A. Crawford in Med. Commun. II. 355 Obtuse trihedral pyramids. 1812Sir H. Davy Chem. Philos. 125 Thus 6 particles may compose an octoedron or triedral prism. 1839–47Todd's Cycl. Anat. III. 267/2 The inferior molars are..divided into two triedral portions. 1878Gurney Crystallogr. 85 The trihedral quoins of the rhombic dodecahedron. 1880Huxley Crayfish iii. 116 Each of these joints is trihedral, the outer face being convex; the inner, flat; and the upper concave.
B. n. Geom. A trihedral figure; the figure determined by three planes meeting at a point (Cent. Dict. Suppl. 1909). Also triˈhedron.
1828Webster, Trihedron, a figure having three equal sides. 1860Worcester cites Davies. |