| 释义 |
icosahedron Geom.|ˌaɪkəʊsəˈhiːdrən, -ˈhɛdrən|
Also 6–8 icosaedrum, 6–9 icosaedron, 7 eicosaedrum, (8 eicosihedron).
[a. Gr. εἰκοσάεδρον, neut. of εἰκοσάεδρος, f. εἴκοσι twenty + ἕδρα seat, base.]
A solid contained by twenty plane faces; spec. the regular icosahedron, contained by twenty equal equilateral triangles.
1570Billingsley Euclid xiii. xvi. 410 The opposite sides of an Icosahedron are parallels. 1571Digges Pantom. iv. def. xvi. T ij b, Icosaedron..marg. Icosaedrum. 1655–87H. More App. Antid. (1712) 183 There are Five regular Bodies..the Cube, the Tetraedrum, the Octaedrum, the Dodecaedrum, and the Eicosaedrum. 1785Reid Int. Powers vi. viii. 658 Five regular solid figures..the tetrahedron..and the eicosihedron. 1881R. Routledge Science i. 25 To each element Plato assigns a geometrical solid: to earth, the cube; to fire, the pyramid; to air, the octahedron; to water, the icosahedron.
Hence icosaˈhedral a., of the form of an icosahedron; having twenty faces.
1828in Webster. 1855Mayne Expos. Lex., Icosihedral. |