Analytical trigonometry, that branch of trigonometry which treats of
the relations and properties of the trigonometrical functions. — Plane
trigonometry, and Spherical trigonometry, those branches of
trigonometry in which its principles are applied to plane triangles and
spherical triangles respectively.
Trig"o*nous (?), a. [L. trigonus, Gr. &?;. See Trigon.] Same as
Trigonal.
Tri"gram (?), n. [Pref. tri- + - gram.] Same as Trigraph.
Tri`gram*mat"ic (?), a. [Gr. &?;; &?; + &?; a letter.] Containing three
letters or characters, or three sets of letters or characters.
Tri*gram"mic (?), a. [Gr. &?;. See Trigrammatic.] Same as Trigrammatic.
Tri"graph (?), n. [Pref. tri- + - graph.] Three letters united in
pronunciation so as to have but one sound, or to form but one syllable,
as -ieu in adieu; a triphthong.
Tri"gyn (?), n. (Bot.) Any one of the Trigynia.
||Tri*gyn"i*a (?), n. pl. [NL., Gr. &?; (see Tri-) + &?; a woman, a
||female.] (Bot.) A Linnæan order of plants having three pistils or
||styles.
||
{ Tri*gyn"i*an (?), Trig"y*nous (?), } a. (Bot.) Having three pistils
or styles; of or pertaining to the Trigynia.
Tri*he"dral (?), a. [See Trihedron.] (Geom.) Having three sides or
faces; thus, a trihedral angle is a solid angle bounded by three plane
angles. [Written also triedral.]
Tri*he"dron (?), n. [Pref. tri- + Gr. &?; a seat, base.] (Geom.) A
figure having three sides.
Tri*ho"ral (?), a. [Pref. tri- + horal.] Occurring once in every three
hours.
Trij"u*gate (?), a. [See Trijugous.] (Bot.) In three pairs; as, a
trijugate leaf, or a pinnate leaf with three pairs of leaflets.
Trij"u*gous (?), a. [L. trijugus threefold; tri- + jugum a yoke.]
(Bot.) Same as Trijugate.
Tri"ko*sane (?), n. [Pref. tri- + Gr. &?; twenty.] (Chem.) A
hydrocarbon, C23H48, of the methane series, resembling paraffin; - - so
called because it has twenty-three atoms of carbon in the molecule.
Tri*lat"er*al (?), a.[L. trilaterus; tri- (see Tri-) + latus, lateris,
side: cf. F. trilatéral. See Lateral.] (Geom.) Having three sides;
being three-sided; as, a trilateral triangle. — Tri*lat"er*al*ly, adv.
— Tri*lat"er*al*ness, n.
Tri*lem"ma (?), n. [NL., fr. Gr. &?; (see Tri-) + &?; any thing
received, in logic, an assumption. Cf. Dilemma.] 1. (Logic) A syllogism
with three conditional propositions, the major premises of which are
disjunctively affirmed in the minor. See Dilemma.
2. A state of things in which it is difficult to determine which one of
three courses to pursue.
Tri*lin"e*ar (?), a. (Math.) Of, pertaining to, or included by, three
lines; as, trilinear coördinates.
Tri*lin"gual (?), a. [L. trilinguis; tri- (see Tri-) + lingua tongue,
language. See Lingual.] Containing, or consisting of, three languages;
expressed in three languages.
The much-noted Rosetta stone . . . bears upon its surface a trilingual
inscription.