If your triangle is a right-angle, then we have these relationships:
Sine Function:
sin(θ) = Opposite / Hypotenuse
Cosine Function:
cos(θ) = Adjacent / Hypotenuse
Tangent Function:
tan(θ) = Opposite / Adjacent
Similar to guest 1 if you have two sides of a right triangle, you can get the hypotenuse using the Pythagorean Theorom a^2 + b^2 = c^2 (a and b are the sides and 'c' is the hypotenuse)
then remember 'SOHCAHTOA'......(sock-uh-toe-uh)
Sine = Opposite / Hypotenuse
Cosine = Adjacent/Hypotenuse
Tangent = Opposite/Adjacent
G'Luck !
