(n.) A set of mathematical rules that enable one to find the angles of a triangle from one other angle and the length of sides, or vice versa. Operates with the help of sine, cosine and tangent (which are actually ratios, but since kids nowdays have scientific calculators nobody cares), and is used in the real world for measuring the height of a structure without expensive equipment. See also cosine rule and pythagoras' threorum
the act of measuring the length of your penis tip during a doggy style sex.
john: wow the tip of my penis is 5cm long
alex: how did u measure it?
john: i did trigonometry with chloe last night dumbass
By Becky
Trigonometry
a mathematical field of study in which you study triangles and their relationships with angles and the unit circle. usually taken after geometry or algebra 2.
You: Have you learned trigonometry yet?
Me: Yup. Sine, cosine, tangent. Secant, cosecant, cotangent.
Geometry and Advanced Algebra got together, and had a baby, named it Trigonometry, and then it grew up. Now it is on tons of steriods and wants to eat you. Commonly called "Trig"