# For an angle Θ with the point (12, -5) on its terminating side, what is the value of cosine?

$\cos \left(\theta\right) = \frac{12}{13}$
The length of the hypotenuse from the origin to $\left(12 , - 5\right)$ can be calculated using the Pythagorean Theorem to be $13$
$\cos = \left(\text{x")/("hypotenuse}\right) = \frac{12}{13}$