The mnemonic SOH CAH TOA was created to help you remember the relevant trig relationships. It is intended to remind you ...
Sin = Opposite/Hypotenuse
sin(θ) = 4/5
Cos = Adjacent/Hypotenuse
cos(θ) = 3/5
Tan = Opposite/Adjacent
tan(θ) = 4/3
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In a right triangle, the opposite side (PQ) is the one that is not part of the angle (∠R = θ). The adjacent side (QR) is the shorter side that makes up the acute angle. The longest side (PR) is the hypotenuse.
