| 释义 |
tetragon, n. (a.)|ˈtɛtrəgɒn|
Also 7 -gone.
[ad. Gr. τετράγωνον a quadrangle: see tetra- and -gon. So late L. tetragōn-um, F. tetragone (14th c. in Godef. Compl.).]
1. Geom. A figure having four angles and four sides; a quadrangle considered as one of the polygons. regular tetragon, a square.
1630S. Lennard tr. Charron's Wisd. (1658) 22 In figures the Pentagone contains the Tetragone. 1690Leybourn Curs. Math. 588 Half the Angle of the Tetragon or Square. 1827Hutton Course Math. I. 283 An Equilateral Triangle is also a Regular Figure of three sides, and the Square is one of four: the former being also called a Trigon, and the latter a Tetragon.
2. A square fort; a quadrangular building or block of buildings. Cf. quadrangle n. 3.
1669Staynred Fortification 1 A Tetragon or Square Fort. 1698Fryer Acc. E. India & P. 57 The Fort is a Tetragone from Corner to Corner. 1884Daily News 5 Feb. 5/7 Populations living in immense tetragons of brick and stone.
b. A quadrangular court surrounded by buildings or walls, e.g. a college quadrangle.
3. Astrol. The aspect of two planets when they are 90° distant from one another relatively to the earth; the square or quadrate aspect.
a1626Bp. Andrewes Serm. (1856) I. 185 In the horoscope of Christ's nativity... Whether a trigon or no, this tetragon I am sure there was. 1727–41Chambers Cycl., Tetragon,..an aspect of two planets with regard to the earth, when they are distant from each other a fourth part of a circle or 90°... The tetragon is expressed by the character {square}. [1819J. Wilson Compl. Dict. Astrol., Tetragonus.]
B. adj. Four-cornered, tetragonal, quadrangular.
1794Morse Amer. Geog. 553 The remains of an ancient..fortification: it is now a regular tetragon terrace, about four feet high, with bastions at each angle. |