Learn more about Learn Trig.
Name a triangle's sides relative to an angle.
Define trig functions as ratios.
Dive deeper into sine's origin.
Match trig functions with ratios of sides.
Pair angles with values of radians, degrees, sine, and cosine.
Since "Tri" means three, "Gon" means angle, and "Metry" means measurements, trigonometry means triangular measurements.
Sin = Opp/Hyp
Cos = Adj/Hyp
Tan = Opp/Adj
Csc = Hyp/Opp
Sec = Hyp/Adj
Cot = Adj/Opp
Sin(-Θ) = -Sin(Θ)
Cos(-Θ) = Cos(Θ)
Tan(-Θ) = -Tan(Θ)
Sin = 1/Csc
Cos = 1/Sec
Tan = 1/Cot
Csc = 1/Sin
Sec = 1/Cos
Cot = 1/Cot
Sin2Θ + Cos2Θ = 1
Tan2Θ + 1 = Sec2Θ
Cot2Θ + 1 = Csc2Θ
Sin(Θ ± π) = Sin(Θ)Cos(π) ± Cos(Θ)Sin(π)
Sin(Θ ± π) = Cos(Θ)Cos(π) ∓ Sin(Θ)Sin(π)
Tan(Θ) ± Tan(π)
Tan(Θ ± π) = ----------------
1 ∓ Tan(Θ)Tan(π)
Θ = Θ * 2π * (± C)
(C is any Integer)