Choosing Trig Functions

$$tan(θ) = \frac{o}{a}$$ where 'o' is the length of the opposite side and 'a' is the length of the adjacent side.

$$sin(θ) = \frac{o}{h}$$ where 'o' is the length of the opposite side and 'h' is the length of the hypotenuse.

$$cos(θ) = \frac{a}{h}$$ where 'a' is the length of the adjacent side and 'h' is the length of the hypotenuse.

$$cot(θ) = \frac{a}{o}$$ where 'a' is the length of the adjacent side and 'o' is the length of the opposite side.

$$sec(θ) = \frac{h}{a}$$ where 'h' is the length of the hypotenuse and 'a' is the length of the adjacent side.

$$csc(θ) = \frac{h}{o}$$ where 'h' is the length of the hypotenuse and 'o' is the length of the opposite side.

Use tangent when you have the lengths of the opposite side and the adjacent side.

Use sine when you have the lengths of the opposite side and the hypotenuse.

Use cosine when you have the lengths of the adjacent side and the hypotenuse.

In a right triangle, the hypotenuse is always opposite the right angle and is the longest side.