trigonometry
Study of triangles
Trigonometry is the branch of mathematics dealing with the relationships between the sides and angles of triangles.
Its core functions—sine, cosine, and tangent—relate angles to ratios of side lengths.
Though rooted in measuring triangles, trigonometry extends to describing periodic phenomena like sound waves, light, and orbital motion: I barely passed trigonometry in high school.
Opposite over hypotenuse
- secantTrig ratio, 1/cos
- cosecantReciprocal of sine
- inverseOpposite in position
- arcsineAngle-recovering trig function
arccosine · arctangent · reciprocal · ratio · identity · unit circle · domain · range
Longest right-triangle side
- oppositeReverse or contrary thing
- adjacentDirectly next to
- scaleneAll sides unequal
- isoscelesTwo sides match
equilateral · Pythagorean · oblique · solving · law of sines · law of cosines · area formula · altitude
Measuring and charting terrain
- navigationDetermining position and course
- theodolitePrecision angle-measuring instrument
- sextantMaritime angular measurement device
- astrolabeAncient altitude-measuring instrument
distance · height · bearing · astronomy · architecture · engineering · physics · GPS
Repeated back-and-forth movement
- waveformGraphed oscillation pattern
- harmonicOf musical overtones
- sinusoidalWave-patterned, mathematically regular
- frequencyRate of recurrence
amplitude · period · phase shift · cycle · Hertz · resonance · vibration · alternating current
Unit of measurement
- acuteIntensely severe or perceptive
- obtuseLacking mental sharpness
- rightMorally proper or entitled
- reflexInvoluntary stimulus response
complementary · supplementary · vertex · bisect · protractor · arc · rotation · inclination
Radius-one circle at origin
- radiusCenter-to-perimeter distance
- circumferenceCircle's outer measurement
- arc lengthCurved segment's measure
- sectorDistinct division of whole
central angle · chord · pi · revolution · quadrant
Of ancient Greek mathematics
- reciprocalShared between two parties
- quotientDivision's numerical result
- cofunctionTrigonometric complement pair
- proofDemonstration of truth
sine
Opposite over hypotenuse
arcsine · arccosine · arctangent · reciprocal · ratio · identity · unit circle · domain · range · periodic
hypotenuse
Longest right-triangle side
isosceles · equilateral · Pythagorean · oblique · solving · law of sines · law of cosines · area formula · altitude · median
surveying
Measuring and charting terrain
- navigationDetermining position and course
- theodolitePrecision angle-measuring instrument
- sextantMaritime angular measurement device
astrolabe · distance · height · bearing · astronomy · architecture · engineering · physics · GPS · cartography
oscillation
Repeated back-and-forth movement
- waveformGraphed oscillation pattern
- harmonicOf musical overtones
- sinusoidalWave-patterned, mathematically regular
frequency · amplitude · period · phase shift · cycle · Hertz · resonance · vibration · alternating current · signal
degree
Unit of measurement
reflex · complementary · supplementary · vertex · bisect · protractor · arc · rotation · inclination · elevation
unit circle
Radius-one circle at origin
- radiusCenter-to-perimeter distance
- circumferenceCircle's outer measurement
- arc lengthCurved segment's measure
sector · central angle · chord · pi · revolution · quadrant
Pythagorean
Of ancient Greek mathematics
- reciprocalShared between two parties
- quotientDivision's numerical result
- cofunctionTrigonometric complement pair
- math practiceaddition, subtraction, multiplication, long division, fractions
- mathaddition, subtraction, multiplication, division, algebra
- math skillsarithmetic, addition, subtraction, multiplication, division
- mathematicsalgebra, arithmetic, calculus, number, addition
- STEMscience, engineering, mathematics, math, technology
- school subjectsmath, English, science, history, reading
trigonometryset theory
Mathematics of abstract collections
algebra · calculus · arithmetic · number theory · statistics
- trigonometric functionsRatios relating angles to sides