trigonometry

[trig-uh-nom-i-tree] /ˌtrɪg əˈnɒm ɪ tri/
noun
1.
the branch of mathematics that deals with the relations between the sides and angles of plane or spherical triangles, and the calculations based on them.
Origin
1605-15; < Neo-Latin trigōnometria; see trigon, -o-, -metry
Related forms
trigonometric
[trig-uh-nuh-me-trik] /ˌtrɪg ə nəˈmɛ trɪk/ (Show IPA), trigonometrical, adjective
trigonometrically, adverb
nontrigonometric, adjective
nontrigonometrical, adjective
nontrigonometrically, adverb
untrigonometric, adjective
untrigonometrical, adjective
untrigonometrically, adverb
British Dictionary definitions for trigonometrical

trigonometry

/ˌtrɪɡəˈnɒmɪtrɪ/
noun
1.
the branch of mathematics concerned with the properties of trigonometric functions and their application to the determination of the angles and sides of triangles. Used in surveying, navigation, etc trig
Derived Forms
trigonometric (ˌtrɪɡənəˈmɛtrɪk), trigonometrical, adjective
trigonometrically, adverb
Word Origin
C17: from New Latin trigōnometria from Greek trigōnon triangle
Word Origin and History for trigonometrical

trigonometry

n.

"branch of mathematics that deals with relations between sides and angles of triangles," 1610s, from Modern Latin trigonometria (Barthelemi Pitiscus, 1595), from Greek trigonon "triangle" (from tri- "three," see tri-, + gonia "angle," see knee (n.)) + metron "a measure" (see meter (n.2)).

trigonometrical in Science
trigonometry
  (trĭg'ə-nŏm'ĭ-trē)   
The study of the properties and uses of trigonometric functions.