When trying to remember the ratio for each trigonometric function,  sine, cosine, tangent, cotangent, secant and cosecant, we really only need to know sine, cosine and tangent. Once we know them, cotangent, secant and cosecant are the recipricol of tangent, cosine and sine, respectively.

In a right triangle, the sine of an angle is the length side opposite the angle divided by the length of the hypotenuse (the side opposite the right angle).

Cosine is the length of the side adjacent to the angle divided by the length of the hypotenuse.

Tangent is the length of the side opposite divided by the length of the side adjacent.

Sine = opposite/hypotenuse

Cosine  = adjacent/hypotenuse

Tangent = opposite/adjacent

Cotangent = 1/tangent

Secant = 1/cosine

Cosecant = 1/sine

Notice that tangent is sine/cosine