I'm guessing that you don't really want the formulas. I think what you actually want is the definitions of those functions of an acute angle when it's in a right triangle.
Cosine = (adjacent side) / (hypotenuse)
Tangent = (opposite side) / (adjacent side)
Sine = (opposite side) / (hypotenuse)
Tell me if I'm wrong, and I'll find some formulas for you.
